vtt 1.15
gtls auto
tRD 10
the 2 settings on top of timings section set on FAST or less
333/666 divider to start

as for your problem with latest bios
is your cpu degraded?
can you run at stock settings stable?
I mean, set the vcore as vid states and frequency and run prime/occt

it works without any problems here.
in fact all the bioses after the last december