Kernel Switch, System does not Boot

[Nanix]

Hello there,
I had an error, with my gpu-driver (Kernel 5.9.1) so I switched to the rt-Kernel, which fixed the error for the first reboot.
Then I did uninstalled the latest Kernel so it wont use it again and rebooted the System. To be safe I got the latest LTS-Kernel 5.4.72-1 installed.
After I rebooted the second time the rt-Kerne does not show up anymore as an boot-option, only the LTS-Kerne 5.4.72.-1.
The problem is, that the system doesn’t boot with the LTS-Kernel and I only get a blackscreen (LENOVO - LOGO).
Is there any chance I can fix this?
I got a Windows 10 as dual boot option which still works fine.
Is there a way to fix this with a live-usb?
I got a timeshift backup, but it is a week old, so would be great if im not forced to use it.
Lenovo ThinkPad T14 (AMD)

[megavolt]

Hi there

Normally mhwd would trigger sudo mkinitcpio -P and then sudo update-grub.

How did you install/remove the kernel?

[Nanix]

@Nanix

With the grafical UI in the Manjaro-Settings.
If this is relevant, I get in tty with (ctrl+ALT+F1) and into the shell when i press e in GRUB and add init=/bin/bash

With the grafical UI in the Manjaro-Settings.
If this is relevant, I get in tty with (ctrl+ALT+F1) and into the shell when i press e in GRUB and add init=/bin/bash

[megavolt]

@Nanix

With the grafical UI in the Manjaro-Settings.

yeah ok… that is mhwd.

@Nanix

I get in tty with (ctrl+ALT+F1)

Then please go into tty3 (with F3), login and run sudo update-grub. If the prefered kernel is not there listed, then try to remove and reinstall it cleanly with:

sudo mhwd-kernel -r linux54

and

sudo mhwd-kernel -i linux58

with

mhwd-kernel -l

you see all possible kernels (-li displays the installed ones)

[Nanix]

Thank you very much sir, if you may leave your Paypal down there I would like to spent you a coffee. you safed me a couple hours of work.
Only thing that didnt work was removing the LTS- Kernel because the system was running on it.