So I have two Z390M Gaming builds. One I use as a PC and is a backup/test bench for hackintosh updates. This backup board is really squirrelly. If I place any PCIE card in Slots 2 or 3 the machine won't post. I'm gonna RMA the board. I just moved the 5700XT to my main rig and it doesn't throw these errors and is installing fine.
I had tried OpenCore and got the same results. I would migrate over to Opencore setup, but I don't want to troubleshoot the consequences of it messing up my iCloud/AppleID/messages. Clover is working really well for me. I was using IGPU for ages, but needed grown up GPU for Davinici.