I have some problems that happen with an old system based on FX-8350/AMD790 and also with a new one based on Ryzen5 2600/AMD350.
I can install the system and run it without problems only with my main GPU, an AMD RADEON R9 380X. But when I changed it to an AMD PRO WX2100, the system can't boot.
When I put installation ISO/UEFI system cant start installation.
When I try to run advance/repair system go into infinite loop.
My 5c:
Problem is, IMHO, in the source of Linux/elementary because I have the same problems with steamOS and it's in the initiation hardware so definitely no drivers issue.