I'm a long time AMD user both my GPU and CPU. I have a powerful enough PSU and a b550m-plus mobo.
I'm looking to do gaming, light AI work, computer programming, running Docker server services.
I have a Radeon 6900xt, but it doesn't work well with Linux anymore. amdgpu fails to load, and I can only boot by adding nomodeset to my boot entry.
With ArchInstall I even tried reformatting with xfs, ext4, btrfs, without encryption, with and without LVM, selecting both ATI OS drivers for all GPUs, and drivers for AMD gpus, with systemd-boot and grub.
Even Fedora on USB only boots with nomodeset.
Windows seems to boot fine.
I assume it may be a problem with system reading the drivers from the GPU.
I have onboard HDMI for graphics, but I've never got it working.
tbh, my 6900XT was too powerful anyways. I do game in 4K with my 55" TV on the highest settings, but it seems I was still barely using the GPUs full potential.
Funny enough, I seem to have had more problems with high end GPUs in the past than low end GPUs.
Hang on...
Just because no one has asked it yet...
Are you only using a HDMI cable and have you not tried a display port cable?
FYI: The "HDMI Forum" didn't want to allow open source implementations of HDMI 2.1. They wanted to charge people a fee for using it. This is why people use display port, it has no fee and it usually has newer feature support earlier.
I dont have a monitor with DP, but I could look into trying a friends monitor. I've only been using HDMI and HDMi 2.1