Your 6.5 kernel is still old. I’d suggest trying a more recent kernel - there have been several AMD-related bugfixes and improvements since then, leading up to the lastest stable 6.8.2. I’d also recommend upgrading to the latest Mesa, which is 24.0.4. Now whilst there are PPAs you can add to easily upgrade your Mesa, I wouldn’t recommend that option as it would introduce more instability and can cause issues with future upgrades. Instead, I’d recommend temporarily trying out a distro with a recent kernel+Mesa, such as Nobara, Bluefin, EndeavourOS etc. If you’re still experiencing issues with them, then it’s likely a hardware issue.