I downloaded the newest image and did a fresh install of Leap 15.4 on a spare Hard Drive of mine. Installed with modprobe.blacklist=amdgpu as kernel options. After that I removed the blacklist and the system booted fine. I confirm that the card works fine with the AMDGPU driver provided by kernel 5.14.21-150400.24.33-default. However, Leap installer still do not work with the AMDGPU loaded.