keyboard Delayed Detection, unable to access BIOS

[Anomnomnomaly]

OK, so I don't know if this would fall under a motherboard issue, or a peripheral one.

 

I've got a Gigabyte Aorus Pro B450 board, and a Corsair Straife keyboard.

 

The motherboard has the gigabyte dual bios, and suffers from the common and well know issue of randomly falling back onto the backup bios... Trust me, if I'd have know about that I wouldn't have bought it.  Now I've managed to work around it over the last 10 months or so because it's random and all I have to do is when it falls back to the backup... which flags it up as a reset bios. I just load the saved profile save and exit... Takes a few seconds and the PC still loads quicker than my old one did. 

 

But the bios is now out of sync, so one is on F42a and the other is F42f... So I'm obviously wanting to flash the backup bios to match... The last time it randomly reset I didn't have my flash drive handy and so simply loaded the saved settings and rebooted.

 

A few days later I decide to flash the bios... except now every time I start up the PC... it's loading windows before the keyboard is detected... so I can't hit del to enter the bios.  I plugged in another older USB keyboard and the same issue. The keyboard doesn't start responding until after windows starts to load.

 

I'm out of keyboards to test, so is there any other kind of tip/trick to try and get into the bios... other than randomly waiting for it to fall over back to the other bios again.