New overclocker here. Looking for advice on how to overclock my 9900k.

[Johan45]

Yeah leave the offset at 1, 1.27 V is fairly low for stability even at 4.9 with the offset if Anthem works the CPU like you are saying after a longer session and things warm up this could be causing it to crash.
An easy test is to drop the AVX offset one more to 2 (4800) if it doesn't crash again then you'll know

 

[crisis88m]

Yeah leave the offset at 1, 1.27 V is fairly low for stability even at 4.9 with the offset if Anthem works the CPU like you are saying after a longer session and things warm up this could be causing it to crash.
An easy test is to drop the AVX offset one more to 2 (4800) if it doesn't crash again then you'll know

I increased to 1.28v left offset at 1 and am stress testing again with aida64. 1 thing I failed to do but didn't think of it is run the cpu and fpu stress test for longer than 1 hour.

This is after 1 hour.

After 2 and a half hours.