So this issue was plaguing me around the same time I thought we might have finally tamed the PSR problems.
While using kernel 6.12, upon resume from sleep, the display would flash to blank.
And it appears I was not the only one, with this first link including a video of the problem;
With this information we might be hopeful that 6.13 works better and that fixes may be backported to 6.12.
Until then I decided to try disabling ABM entirely using boot option amdgpu.abmlevel=0.
It seems to have worked around the issue so far.