ThunderboltEX II + Big Sur: Not working

I managed to get Big Sur on my x99 Rog Strix + i7-6900k + AMD Rx480.
However, the ThunderboltEX 2 card (which worked on high Sierra on same computer) does not seem to work.

Anyone got this working on Big Sur?
Is this possibly a kext issue?

Any help appreciated

MD

Author: mightydood2