Removing power during post does not resolve issues.
If I execute Windows soft shut down and prior to post remove the power (unplug ac) form either all or any two of three monitors then I can post and switch BIOS. It also works when I unplug any two or all display ports.
Just softly shutting down my system without unplugging or removing monitors/displayports results in the code 00 and the inability to switch BIOS issues.
I’ve also tried mixing connection types (i.e. one DVI / two display ports and two DVI / one display port) resulting in exactly the same issues.
My monitors are ASUS VE278Q.