Trouble with Display Manager and NVIDIA Driver

Hello,

I am running RHEL8 on an intel i9 Workstation with a Quadro RTX4000 GPU.

This system always was a little problematic since I configured it to come up in runlevel 5.

The GUI was sometimes not visible and I had to login remotely (via ssh) and restart GDM before Gnome came up again.

However, some time ago, I got rid of GNOME and installed XFCE4 instead. Moreover, I configured the system to come up in runlevel 3 and got used to starting XFCE4 manually, whenever I was working locally on the machine.

Recently, I tried to install lightdm as an alternative greeter. However, I did not succeed: I needed to install with the --allowerasing flag and afterwards my X was damaged (i.e. the screen was black).

To repair the machine, I logged in remotely again, un-installed X-Windows, re-installed it and I also had to reinstall nvidia-settings

Now, everything is (almost) like before again: I still have no greeter (which is not important, of course) and I boot into runlevel 3. From there, I can start XFCE4.

But when I update (via dnf upgrade) I get the following error reported:

Problem 1: package nvidia-settings-3:440.33.01-1.el8.x86_64 requires nvidia-libXNVCtrl(x86-64) = 3:440.33.01-1.el8, but none of the providers can be installed
- cannot install both nvidia-libXNVCtrl-3:440.82-1.el8.x86_64 and nvidia-libXNVCtrl-3:440.33.01-1.el8.x86_64
- cannot install the best update candidate for package nvidia-settings-3:440.33.01-1.el8.x86_64
- cannot install the best update candidate for package nvidia-libXNVCtrl-3:440.33.01-1.el8.x86_64
Problem 2: problem with installed package nvidia-settings-3:440.33.01-1.el8.x86_64
- package nvidia-settings-3:440.33.01-1.el8.x86_64 requires nvidia-libXNVCtrl(x86-64) = 3:440.33.01-1.el8, but none of the providers can be installed
- cannot install both nvidia-libXNVCtrl-3:440.82-1.el8.x86_64 and nvidia-libXNVCtrl-3:440.33.01-1.el8.x86_64
- package nvidia-libXNVCtrl-devel-3:440.82-1.el8.x86_64 requires nvidia-libXNVCtrl = 3:440.82-1.el8, but none of the providers can be installed
- cannot install the best update candidate for package nvidia-libXNVCtrl-devel-3:440.33.01-1.el8.x86_64
- package nvidia-settings-3:440.64-1.el8.x86_64 is excluded
- package nvidia-settings-3:440.82-1.el8.x86_64 is excluded
(try to add '--allowerasing' to command line to replace conflicting packages or '--skip-broken' to skip uninstallable packages or '--nobest' to use not only best candidate packages)

What can I do to resolve this?

Actually, I am a bit afraid of using nobest/allowerasing again.

Fixing the damaged X took me some hours recently - and I dramatically depend on this system currently.

Are there some safe options, which I could try to fix my RHEL8 (which will not damage my X again).

Any advice would be greatly appreciated!