Black screen to entire PC Freeze after 60+ seconds

I was running this perfectly fine on my 6900xt.. upgraded to a 7900xtx AND updated my BIOS and now it just freezes, then reboots the PC & suddenly my GPU driver is broken & I have to reinstall...
The most common fix seems to be underclocking the GPU as the driver downgrades don't seem to change anything either, but this hasn't worked for me either.
AMD Dropped the much newer 26.7.1 driver which works across ALL games but BF6..
Any ideas?