Fedora 32 Live DVD ISO Fails

AFAIK fedora still supports radeon graphics. It seems to have the alternative of amdgpu or radeon drivers.
With your inability to boot to the F32 install, and the ability to boot to F21 install I am led to suspect the issue may actually be in the bios.

I know for a fact that F21 supported legacy BIOS with MBR formatted boot sector.
I believe F32 expects UEFI bios with GPT formatted boot sector and quite possibly that is the only BIOS it supports.

I am not the definitive source for this, but if I am right and F32 will not operate with legacy BIOS then the issue could be that the mobo of your system is simply not capable of operating with F32 Workstation.

Can you possibly do a netinstall of F32? You also might be able to do a server install instead of the workstation install since AFAIK it does not use the same graphical install interface.