Two MSI Z270 SLI PLUS have different graphic output quality (BIOS mod?)

I have two MSI Z270 SLI PLUS motherboards with intent to install matching hardware /software configuration. Unfortunately, they are not identical: one has BIOS E7A59IMS.140 from 12/15/2016, the other – E7A59IZ1.1J1 from 07/06/2017:

v.140 v.1J1

First puzzle: current highest official BIOS version is 7A59v1A from 2018-07-17.
M-Flash recognizes E7A59IMS.1A0 file on the first mobo (14), but not on the second. I attribute that to 1A being less than 1J, but would like to have a confirmation.
Even so, i can’t explain dates being out of order.

Googling E7A59IZ1.1J1 results in only two links, and a related direct file URL. So, this may not be an official BIOS?
Is there a way to re-flash 1J to official one (1A)?

Both sets (mobo + cpu + ram) have passed rigorous (24+ hrs) MemTest86 v7.3.

Next, Windows setup (from the same USB drive) looks normal on 14: v.140

but has dithered color depth on 1J: v.1J1 and lower resolution (dialog fills entire screen): v.1J1 occasionally with color (and in Classic theme!): v.1J1

Since CPU graphics is used on both, is this a result of BIOS mod on 1J, or 2nd CPU is somehow damaged? (I thought about swapping CPUs, but haven’t gotten to it yet, will try next)

Dual boot (Ubuntu 18.04 with Windows 10) on Motherboard MSI Gaming M5 Z270

I’m trying to install dual boot on my pc, but i can’t because when i load the installation, my screen stays black and i can’t do anything in there excepet shutdown or reboot the pc to Windows 10. I already cleared CMOS manually, load optimized values default, disable fast boot, enable/disable secure boot and reinstalled Windows 10 and everything i done was useless. Any ideas how to solve this problem ??