Question 1 of 2 installed GPUs won't post ?

May 17, 2021
Hi, so I got the following problem:
My hardware:
Ryzen 7 2700X
ASRock B450M Pro4
RX 5700XT
Nvidia GT 710
I want to passthrough my main gpu to a VM guest system. My first GPU (RX5700XT) is in the PCI 8x slot (closest to the CPU). The GT 710 is in the PCI 1x slot directly next to the CPU. My problem is, that I do not get any post messages when only the GT 710 is plugged in to my two monitors. If I put one monitor on the 5700 and one on the GT710 I get the post messages on the monitor of the 5700 and when Im booted into linux both monitors work fine. I figured that the 5700 has some sort of priority, even though no display is connected to it. My problem now is, that when passing through the GPU I need to bind the 5700 with a vfio dummy driver in linux, which prevents the normal drivers from loading for the card. This though, results in me not getting any linux boot messages and not beeing able to login as the GT710 only seems to load when my linux desktop session has fully started. So my question is, is there any way to "change" the priority gpu for the bios or linux boot process. Any other advice is greatly appreciated.
Thanks in advance