Bootloader does not recognize current kernel

you open it with your text editor, i dont know which one you are using, but im on kde, and using kate, so the command is:
kate /boot/grub/grub.cfg
you replace kate with your text editor name, and then use the search function in your text editor

no matches were found against what you wrote, but here is the file

#
# DO NOT EDIT THIS FILE
#
# It is automatically generated by grub-mkconfig using templates
# from /etc/grub.d and settings from /etc/default/grub
#

### BEGIN /etc/grub.d/00_header ###
insmod part_gpt
insmod part_msdos
if [ -s $prefix/grubenv ]; then
  load_env
fi
if [ "${next_entry}" ] ; then
   set default="${next_entry}"
   set next_entry=
   save_env next_entry
   set boot_once=true
else
   set default="${saved_entry}"
fi

if [ x"${feature_menuentry_id}" = xy ]; then
  menuentry_id_option="--id"
else
  menuentry_id_option=""
fi

export menuentry_id_option

if [ "${prev_saved_entry}" ]; then
  set saved_entry="${prev_saved_entry}"
  save_env saved_entry
  set prev_saved_entry=
  save_env prev_saved_entry
  set boot_once=true
fi

function savedefault {
  if [ -z "${boot_once}" ]; then
    saved_entry="${chosen}"
    save_env saved_entry
  fi
}

function load_video {
  if [ x$feature_all_video_module = xy ]; then
    insmod all_video
  else
    insmod efi_gop
    insmod efi_uga
    insmod ieee1275_fb
    insmod vbe
    insmod vga
    insmod video_bochs
    insmod video_cirrus
  fi
}

set menu_color_normal=light-gray/black
set menu_color_highlight=green/black

if [ x$feature_default_font_path = xy ] ; then
   font=unicode
else
insmod part_gpt
insmod f2fs
set root='hd0,gpt2'
if [ x$feature_platform_search_hint = xy ]; then
  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2  8e90632f-9f93-415f-a3a7-d8e866b93df9
else
  search --no-floppy --fs-uuid --set=root 8e90632f-9f93-415f-a3a7-d8e866b93df9
fi
    font="/usr/share/grub/unicode.pf2"
fi

if loadfont $font ; then
  set gfxmode=auto
  load_video
  insmod gfxterm
  set locale_dir=$prefix/locale
  set lang=en_US
  insmod gettext
fi
terminal_input console
terminal_output gfxterm
insmod part_gpt
insmod f2fs
set root='hd0,gpt2'
if [ x$feature_platform_search_hint = xy ]; then
  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2  8e90632f-9f93-415f-a3a7-d8e866b93df9
else
  search --no-floppy --fs-uuid --set=root 8e90632f-9f93-415f-a3a7-d8e866b93df9
fi
insmod gfxmenu
loadfont ($root)/usr/share/grub/themes/manjaro/dejavu_sans_12.pf2
loadfont ($root)/usr/share/grub/themes/manjaro/dejavu_sans_14.pf2
loadfont ($root)/usr/share/grub/themes/manjaro/dejavu_sans_16.pf2
loadfont ($root)/usr/share/grub/themes/manjaro/dejavu_sans_24.pf2
loadfont ($root)/usr/share/grub/themes/manjaro/dejavu_sans_48.pf2
loadfont ($root)/usr/share/grub/themes/manjaro/dejavu_sans_bold_16.pf2
loadfont ($root)/usr/share/grub/themes/manjaro/dejavu_sans_mono_12.pf2
loadfont ($root)/usr/share/grub/themes/manjaro/terminus-12.pf2
loadfont ($root)/usr/share/grub/themes/manjaro/terminus-14.pf2
loadfont ($root)/usr/share/grub/themes/manjaro/terminus-16.pf2
loadfont ($root)/usr/share/grub/themes/manjaro/terminus-18.pf2
loadfont ($root)/usr/share/grub/themes/manjaro/terminus-b12.pf2
loadfont ($root)/usr/share/grub/themes/manjaro/terminus-b14.pf2
loadfont ($root)/usr/share/grub/themes/manjaro/terminus-b16.pf2
loadfont ($root)/usr/share/grub/themes/manjaro/terminus-b18.pf2
insmod png
set theme=($root)/usr/share/grub/themes/manjaro/theme.txt
export theme
if [ x$feature_timeout_style = xy ] ; then
  set timeout_style=hidden
  set timeout=5
# Fallback hidden-timeout code in case the timeout_style feature is
# unavailable.
elif sleep --interruptible 5 ; then
  set timeout=0
fi
### END /etc/grub.d/00_header ###

### BEGIN /etc/grub.d/10_linux ###
menuentry 'Manjaro Linux' --class manjaro --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-simple-8e90632f-9f93-415f-a3a7-d8e866b93df9' {
	load_video
	set gfxpayload=keep
	insmod gzio
	insmod part_gpt
	insmod f2fs
	set root='hd0,gpt2'
	if [ x$feature_platform_search_hint = xy ]; then
	  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2  8e90632f-9f93-415f-a3a7-d8e866b93df9
	else
	  search --no-floppy --fs-uuid --set=root 8e90632f-9f93-415f-a3a7-d8e866b93df9
	fi
	linux	/boot/vmlinuz-5.18-x86_64 root=UUID=8e90632f-9f93-415f-a3a7-d8e866b93df9 rw  quiet apparmor=1 security=apparmor udev.log_priority=3
	initrd	/boot/amd-ucode.img /boot/initramfs-5.18-x86_64.img
}
submenu 'Advanced options for Manjaro Linux' $menuentry_id_option 'gnulinux-advanced-8e90632f-9f93-415f-a3a7-d8e866b93df9' {
	menuentry 'Manjaro Linux (Kernel: 5.18.2-1-MANJARO x64)' --class manjaro --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.18.2-1-MANJARO x64-advanced-8e90632f-9f93-415f-a3a7-d8e866b93df9' {
		load_video
		set gfxpayload=keep
		insmod gzio
		insmod part_gpt
		insmod f2fs
		set root='hd0,gpt2'
		if [ x$feature_platform_search_hint = xy ]; then
		  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2  8e90632f-9f93-415f-a3a7-d8e866b93df9
		else
		  search --no-floppy --fs-uuid --set=root 8e90632f-9f93-415f-a3a7-d8e866b93df9
		fi
		linux	/boot/vmlinuz-5.18-x86_64 root=UUID=8e90632f-9f93-415f-a3a7-d8e866b93df9 rw  quiet apparmor=1 security=apparmor udev.log_priority=3
		initrd	/boot/amd-ucode.img /boot/initramfs-5.18-x86_64.img
	}
	menuentry 'Manjaro Linux (Kernel: 5.18.2-1-MANJARO x64 - fallback initramfs)' --class manjaro --class gnu-linux --class gnu --class os $menuentry_id_option 'gnulinux-5.18.2-1-MANJARO x64-fallback-8e90632f-9f93-415f-a3a7-d8e866b93df9' {
		load_video
		set gfxpayload=keep
		insmod gzio
		insmod part_gpt
		insmod f2fs
		set root='hd0,gpt2'
		if [ x$feature_platform_search_hint = xy ]; then
		  search --no-floppy --fs-uuid --set=root --hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2  8e90632f-9f93-415f-a3a7-d8e866b93df9
		else
		  search --no-floppy --fs-uuid --set=root 8e90632f-9f93-415f-a3a7-d8e866b93df9
		fi
		linux	/boot/vmlinuz-5.18-x86_64 root=UUID=8e90632f-9f93-415f-a3a7-d8e866b93df9 rw  quiet apparmor=1 security=apparmor udev.log_priority=3
		initrd	/boot/initramfs-5.18-x86_64-fallback.img
	}
}

### END /etc/grub.d/10_linux ###

### BEGIN /etc/grub.d/20_linux_xen ###
### END /etc/grub.d/20_linux_xen ###

### BEGIN /etc/grub.d/30_os-prober ###
### END /etc/grub.d/30_os-prober ###

### BEGIN /etc/grub.d/30_uefi-firmware ###
menuentry 'UEFI Firmware Settings' $menuentry_id_option 'uefi-firmware' {
	fwsetup
}
### END /etc/grub.d/30_uefi-firmware ###

### BEGIN /etc/grub.d/35_fwupd ###
### END /etc/grub.d/35_fwupd ###

### BEGIN /etc/grub.d/40_custom ###
# This file provides an easy way to add custom menu entries.  Simply type the
# menu entries you want to add after this comment.  Be careful not to change
# the 'exec tail' line above.
### END /etc/grub.d/40_custom ###

### BEGIN /etc/grub.d/41_custom ###
if [ -f  ${config_directory}/custom.cfg ]; then
  source ${config_directory}/custom.cfg
elif [ -z "${config_directory}" -a -f  $prefix/custom.cfg ]; then
  source $prefix/custom.cfg
fi
### END /etc/grub.d/41_custom ###

### BEGIN /etc/grub.d/41_snapshots-btrfs ###
### END /etc/grub.d/41_snapshots-btrfs ###

### BEGIN /etc/grub.d/60_memtest86+ ###
if [ "${grub_platform}" == "pc" ]; then
    menuentry "Memory Tester (memtest86+)" --class memtest86 --class gnu --class tool {
        search --fs-uuid --no-floppy --set=root --hint-bios=hd0,gpt2 --hint-efi=hd0,gpt2 --hint-baremetal=ahci0,gpt2  8e90632f-9f93-415f-a3a7-d8e866b93df9
        linux16 /boot/memtest86+/memtest.bin 
    }
fi
### END /etc/grub.d/60_memtest86+ ###


Omg, just run the command to the end and reinstall them and post ALL output.

warning: linux519-5.19.1-3 is up to date -- reinstalling
warning: linux519-headers-5.19.1-3 is up to date -- reinstalling
resolving dependencies...
looking for conflicting packages...

Packages (2) linux519-5.19.1-3  linux519-headers-5.19.1-3

Total Installed Size:  325.00 MiB
Net Upgrade Size:        0.00 MiB

:: Proceed with installation? [Y/n] y
(2/2) checking keys in keyring                                                                                                                                                                [#######################################################################################################################] 100%
(2/2) checking package integrity                                                                                                                                                              [#######################################################################################################################] 100%
(2/2) loading package files                                                                                                                                                                   [#######################################################################################################################] 100%
(2/2) checking for file conflicts                                                                                                                                                             [#######################################################################################################################] 100%
(2/2) checking available disk space                                                                                                                                                           [#######################################################################################################################] 100%
:: Running pre-transaction hooks...
(1/1) Creating Timeshift snapshot before upgrade...
==> skipping timeshift-autosnap due skipRsyncAutosnap in /etc/timeshift-autosnap.conf set to TRUE.
:: Processing package changes...
(1/2) reinstalling linux519                                                                                                                                                                   [#######################################################################################################################] 100%
(2/2) reinstalling linux519-headers                                                                                                                                                           [#######################################################################################################################] 100%
:: Running post-transaction hooks...
(1/5) Arming ConditionNeedsUpdate...
(2/5) Updating module dependencies...
(3/5) Updating linux initcpios...
==> Building image from preset: /etc/mkinitcpio.d/linux519.preset: 'default'
  -> -k /boot/vmlinuz-5.19-x86_64 -c /etc/mkinitcpio.conf -g /boot/initramfs-5.19-x86_64.img
==> Starting build: 5.19.1-3-MANJARO
  -> Running build hook: [base]
  -> Running build hook: [udev]
  -> Running build hook: [autodetect]
  -> Running build hook: [modconf]
  -> Running build hook: [block]
==> WARNING: Possibly missing firmware for module: xhci_pci
  -> Running build hook: [keyboard]
  -> Running build hook: [keymap]
  -> Running build hook: [consolefont]
==> WARNING: consolefont: no font found in configuration
  -> Running build hook: [filesystems]
  -> Running build hook: [fsck]
==> Generating module dependencies
==> Creating gzip-compressed initcpio image: /boot/initramfs-5.19-x86_64.img
==> Image generation successful
==> Building image from preset: /etc/mkinitcpio.d/linux519.preset: 'fallback'
  -> -k /boot/vmlinuz-5.19-x86_64 -c /etc/mkinitcpio.conf -g /boot/initramfs-5.19-x86_64-fallback.img -S autodetect
==> Starting build: 5.19.1-3-MANJARO
  -> Running build hook: [base]
  -> Running build hook: [udev]
  -> Running build hook: [modconf]
  -> Running build hook: [block]
==> WARNING: Possibly missing firmware for module: bfa
==> WARNING: Possibly missing firmware for module: qed
==> WARNING: Possibly missing firmware for module: qla1280
==> WARNING: Possibly missing firmware for module: qla2xxx
==> WARNING: Possibly missing firmware for module: xhci_pci
  -> Running build hook: [keyboard]
  -> Running build hook: [keymap]
  -> Running build hook: [consolefont]
==> WARNING: consolefont: no font found in configuration
  -> Running build hook: [filesystems]
  -> Running build hook: [fsck]
==> Generating module dependencies
==> Creating gzip-compressed initcpio image: /boot/initramfs-5.19-x86_64-fallback.img
==> Image generation successful
(4/5) Refreshing PackageKit...
(5/5) Updating Grub-Bootmenu
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-5.19-x86_64
Found initrd image: /boot/amd-ucode.img /boot/initramfs-5.19-x86_64.img
/usr/bin/grub-probe: error: unknown filesystem.
Found initrd fallback image: /boot/initramfs-5.19-x86_64-fallback.img
Found linux image: /boot/vmlinuz-5.19-rt-x86_64
Found initrd image: /boot/amd-ucode.img /boot/initramfs-5.19-rt-x86_64.img
Found initrd fallback image: /boot/initramfs-5.19-rt-x86_64-fallback.img
Warning: os-prober will be executed to detect other bootable partitions.
Its output will be used to detect bootable binaries on them and create new boot entries.
Adding boot menu entry for UEFI Firmware Settings ...
error: command failed to execute correctly
```

in the grub.cfg, there are only entries for the 5.18 kernel…
and in the installation output you have this:

Well you definitely didn’t just install and remove a kernel. Btw, why do you need RT kernel? Just remove it and never install it again.

Also explain this reply to Brahma:

What’s the location of it then?

Also, please post: lsblk

I looks like the 5.18 kernel is not installed even though you say you can run it. If thats the kernel you want to run you might want to try and reinstall the 5.18 kernel.
A little off topic, but its a good idea to have at least 2 different kernels installed. If you have only one a bad upgrade can make your system unusable.

Maybe it is the best for you to install the kernel via chroot from live-USB:

How to boot from USB into live Manjaro (for repair):

Please install 2 kernels (one of them LTS)

no, i cant run linux 5.18. What i have to do is manually edit some prompt every time i boot to launch with 5.19

I do have linux 5.19. Grub is wrong about that
the otpout of lsblk is
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINTS
sda 8:0 0 931.5G 0 disk
├─sda1 8:1 0 300M 0 part /boot/efi
└─sda2 8:2 0 931.2G 0 part /

Do you need the 5.19 kernel for specific hardware needs? 5.19 is an experimental kernel, just making sure.

I dont think so, but its not an lts release so it will stop receiving patches

Kernels are mostly for hardware support. My advise if you dont need the 5.19 kernel for a specific pieces of new hardware is install a LTS kernel like 5.15 and remove the 5.19 kernel(s).

one of the recent kernels greatly improved f2fs support, the file system i use

@brahma that is what grub-probe may be referring to with unknown file system

The choice is yours, 5.19 isnt working for you, but if your ok with how your booting in exchange for some file sustem improvements, have fun.

Alternately as a work around, edit /etc/grub.d/40_custom. Copy the 5.18 section from your /boot/grub/grub.cfg starting from menuentry to the } before the next submenu or menuentry below it to 40_custom. Edit it as your editing during boot to make it into 5.19. Save it then run update-grub as root. It should add another boot entry to grub that will load the 5.19 kernel.

What (if any) output you get running:

sudo tune2fs -l /dev/sda2 | grep metadata_csum_seed 

the result is

tune2fs: Bad magic number in super-block while trying to open /dev/sda2

Ok. So I guess you aren’t using ext4?

Output of (don’t quote it, use preformatted text </>):

sudo blkid

i am using f2fs. the output is :

/dev/sda2: UUID="8e90632f-9f93-415f-a3a7-d8e866b93df9" BLOCK_SIZE="4096" TYPE="f2fs" PARTLABEL="root" PARTUUID="139b3b3c-b33d-8942-b28c-a69f76f81a6c"
/dev/sda1: LABEL_FATBOOT="NO_LABEL" LABEL="NO_LABEL" UUID="E102-2D1D" BLOCK_SIZE="512" TYPE="vfat" PARTUUID="eae7477d-a5fe-234a-be3f-ad1c4cfbba0b"