How is anybody getting around this issue

Here's what i have and have tried.

z170a pro gaming  msi
z270a pro  msi

I can get all 6 rx580 or rx570 to work fine.

When i flash the bios on any card. Even just a single card. That card will show no video until it hits windows
 
It is impossible to get into bios unless unplugging all cards.

The biggest problem is makes is the computer doesn't see the graphics card until it hits windows. And because of that msi afterburner thinks the computer loaded on the Intagrated graphics and can't adjust volts and sometimes clocks because of it. What i think is going on is flashing messes something up with uefi.

Please help
Never have video until windows with any flashed cards. rx480, rx570, rx580. on these 2 boards.