i see, then it's most probably a hardware/bios issue
have you tried setting bios back to stock? including running your ram at JEDEC speed (non XMP/DOCP, 2133MHz)
by fresh install, did you use a windows installer USB stick?
BIOS definitely isn't the issue, I can positively say. Hardware is questionable.
Everything has been at stock/defaults since mid July.
What seems to have fixed my problem, however, was refresh rate. For some odd reason going above 120Hz on my ASUS TUF Gaming VG279QM I got last year destroys everything. Yes, I have used a new cable and different GPU. Very disappointing.
Other things I did was get a 1300W PSU and go back to Windows 11. Before installing the OS, I made everything at stock except A-XMP. I have 3200 instead of 3600 since on the 3900x specifications it states 3200. I'm leaving the GPU do its' own thing and PBO off.
If anyone has a recommendation for a new monitor, do let me know.