Question Tightening RAM timings makes PC freeze & less responsive without any error in Memtest86 pro ?

[MysticHacker]

I wonder why after tightening timings makes my PC freeze & less responsive, sometimes without any error in Memtest86 Pro in 6 passes with no error ? ( but having better benchmark).
(I use gear 2 so the latency is more than 60ns)

Both at 1.3v. I have also try to 1.36v but nothing changes.
Kingmax 2400 Undefined ic chip die of SKnix.

 

[MysticHacker]

System freeze/halt can be the result of several possible causes: Bug in UEFI BIOS firmware (Most common cause); Bad RAM & other hardware; Bad memory map This type of bug tends to be very repeatable (not random) The BIOS in a computer maintains a memory map of available free memory and used memory.

So with this case, in your opinion, I should have better wait for the BIOS update or set the RAM timings back to the old one is the last hope, is it right?
(English is not my mother language, I will so the most respectful to you as I know how to in my sentences.)