Bootloader does not recognize current kernel

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"

the bootloader doesnt recognize any kernel but 5.18

So, my guess, something happened to f2fs filesystem and grub fails updating.

Try running fsck.f2fs on root partition. Also check: F2FS - ArchWiki

Another thing you can do and post here is enable debug messages in GRUB before running update-grub: GRUB - ArchWiki