well your system is still messed up, maybe because of this?:
since you can boot with a newer kernel into manjaro live usb…
and yes install back the nvidia drivers:
sudo mhwd -a pci nonfree 0300
reboot
As you may imagine, I don’t know at all what it means
(Just a noob)
But yeah it must be messed up somehow!
“pEp” I can only associate with “Pretty Easy Privacy” which I once tried. But what should it have to do with failed logins, booting and stuff?
BTW
Now I can choose Xorg on the login screen…
post output from:
systemctl --failed
to see if the same service is failed on the 5.10
i didnt found the Pretty Easy Privacy package, what is that, where did you installed it from?
so try using xorg, and install also back the nvidia drivers
systemctl --failed
UNIT LOAD ACTIVE SUB DESCRIPTION
0 loaded units listed.
Certainly the “pEp-update…” must be something else… I don’t know 
So now I have a problem again.
I did sudo mhwd -a pci nonfree 0300
Then I removed the 6.x kernel (because I thought that’s ok and I won’t need it anymore.
Then I rebooted getting the same old login loop. Then I thought I could do sudo mhwd -r pci video-hybrid-intel-nvidia-prime, to undo sudo mhwd -a pci nonfree 0300 and undo the new login loop. But it didn’t help, so I_m back to: 
I guess I’ll have to come back to this tomorrow…
Sorry, you should stop helping me!
so booting with the kernel 5.10 doesnt work?
post picture of this:
mhwd-kernel -li && mhwd -li
and:
find /etc/X11/ -name "*.conf"
I don’t know if it makes sense, but I’m trying to redo some of the earlier steps, like the following…
[manjaro-gnome /]# ls /etc/mkinitcpio.d/*.preset
/etc/mkinitcpio.d/linux510.preset /etc/mkinitcpio.d/linux61.preset
/etc/mkinitcpio.d/linux515.preset
[manjaro-gnome /]# ls /boot/initramfs-*
/boot/initramfs-5.10-x86_64-fallback.img
/boot/initramfs-5.10-x86_64.img
/boot/initramfs-5.15-x86_64-fallback.img
/boot/initramfs-5.15-x86_64.img
[manjaro-gnome /]# ls /boot/vmlinuz-*
/boot/vmlinuz-5.10-x86_64 /boot/vmlinuz-5.15-x86_64
[manjaro-gnome /]# ls /usr/lib/modules/*
/usr/lib/modules/5.10.161-1-MANJARO:
extramodules modules.builtin.alias.bin modules.order
kernel modules.builtin.bin modules.softdep
kernelbase modules.builtin.modinfo modules.symbols
modules.alias modules.dep modules.symbols.bin
modules.alias.bin modules.dep.bin pkgbase
modules.builtin modules.devname vmlinuz
/usr/lib/modules/5.15.85-1-MANJARO:
extramodules modules.builtin.alias.bin modules.order
kernel modules.builtin.bin modules.softdep
kernelbase modules.builtin.modinfo modules.symbols
modules.alias modules.dep modules.symbols.bin
modules.alias.bin modules.dep.bin pkgbase
modules.builtin modules.devname vmlinuz
/usr/lib/modules/extramodules-5.10-MANJARO:
version
/usr/lib/modules/extramodules-5.15-MANJARO:
version
[manjaro-gnome /]# head /etc/mkinitcpio.conf
# vim:set ft=sh
# MODULES
# The following modules are loaded before any boot hooks are
# run. Advanced users may wish to specify all system modules
# in this array. For instance:
# MODULES=(piix ide_disk reiserfs)
MODULES=(i915 nvidia nvidia_drm nvidia_uvm nvidia_modeset)
# BINARIES
# This setting includes any additional binaries a given user may
from tty reinstall the video drivers, so remove them first:
sudo mhwd -r pci video-modesetting
sudo mhwd -r pci video-linux
install them:
sudo mhwd -a pci free 0300
reboot
Done. But still no login.
very interesting…
do you have downloaded the latest manjaro iso? if yes boot with it, select proprietary drivers, and check if you can boot without problems… if yes, maybe a reinstallation is in place… before that backup your browser folder in your home directory, and some other programs that you may use and reinstall it…
Yeah I thought about it too.
Shouldn’t the Live USB which I created some days ago be the latest iso?
So far I have booted with open source drivers when using it. So you propose to check the other option?
I think reinstalling will require me to be cautious, as I have dual boot etc.
Sure there are a million how tos out there, but if you have a recommendation, let me know.
I really appreciate your help.
I think I’ll stick with Manjaro and tell people about it, maybe I’ll donate in the future.
So hopefully it wasn’t worhtless and annoying for you to help me.
yes boot the usb with proprietary (nvidia) drivers to see if you can…
if yes in the installation screen select install alongside, select the manjaro partition, and thats it, the installation take cares of the rest…
Okay…
What do you mean with the browser folder?
I would tend to backup all of the home folder if possible.
Would that be possible in the Live USB using chroot and then copying the stuff to an external Harddrive?
the firefox folder or brave folder in your home…
but again, boot the usb with proprietary drivers, to see if you can do it…
you can back up your files via the file manager
Is it a problem when it looks like there’s a partition for root and one for home?
Should they be merged before? With gparted?
And how do I have to handle the encryption for install from Live USB session?
I can decrypt them with cryptsetup open /dev/nmve.... [name], can I then just run the installation “wizard”? Looks like it would work.
i dont use encyption, so dont know, but you can try it like that… but if you have a separate home partition, you could only reinstall the root and dont format the home partition, just mount it as home… but im not sure in this case… the important thing is, that you have backup of your files…
Maybe I’ll try.
I guess there’s a way to set the mounting of the home partition up so that it works like now, automatically.
But mayb to be sure I would delete both paritions, merge them into one and do the installation on the new merged partition. Thx
so everything worked?