I have ran into a problem with Kubuntu, on a new Ryzen 9 5900x build, with an MSI B550 Tomahawk board, and an MSI 4080 Super Expert GPU. I decided to reinstall Kubuntu after moving from an older build with a Ryzen 7 2700x, and a 1080 Ti, on an old MSI X470 Gaming Plus board. I am using the same RAM, PSU, SSDs, and hard drives as on the old Ryzen 7 build.

In any case, I can't get the new install (which I've redone several times over the last day) to boot properly, because the boot sequence always hangs on something. I had to remove "splash quiet" from my grub config to see what was doing it though.

First time around, it was snapd it hung on, and I purged that to try to deal with it (in tty2), and then on the reboot it hung up cups.service, and I uninstalled that as well, but on the next boot it hung up on Plymouth-quit.service. I figure it's possible I made things worse but I am not sure how to resolve the issue. I've not been able to login normally with Kubuntu since I put this new machine together yesterday, and every time I get into Plasma with startx (via tty2) I end up stuck at 1024x768 @ 76hz.

I figure I'll try a fresh install again, if I can figure out how to prevent snapd to from hanging, but until then I don't what I'm supposed to do here. The only saving grace is that I have a dual boot system with Windows on a second SSD, so if Linux has issues, I can use Windows, although I am not that fond of it.

Anyone had experience with this issue?

I guess the first thing would be to make sure the BIOS is updated to the latest version on the motherboard. Sometimes that solves a lot of 'inconsistent' problems. Then don't tweak anything (like up the memory speed, etc.) until all is running as it should. I use Gigabyte motherboards so not much help there! BTW, I have a 5900X running on a Gigabyte motherboard with KUbuntu 23.10 on it. Rock solid.

Another suggestion is to swap back to the 1080Ti GPU to see if that solves the problem. At least you might be able to help find out what is at fault.

The BIOS version I have is about a year old. I tried to flash it, but Mflash (the MSI flash utility) reboots to a blank screen and I get nothing. I read somewhere that Mflash requires a HDMI output, and I don't appear to have a working HDMI cord.

However, I am installing MSI Center now, and I think that can update the BIOS as well. I try that and see what happens.

Update: I did manage to update my BIOS to the latest version, which made no difference. I also tried using my 1080 Ti and the same thing happened. It made no difference either.

Well... I may just try returning this motherboard after I order something else. I have about month to do that, so it should be easy to do.
This board has other issues, such as rebooting to a blank screen (ie, no video feed on reboot). Maybe I'll have better luck with some other brand, even. I was thinking
about trying the ASRock X570 PG Velocita, which is only a little more than this B550 board, on NewEgg.