It works with latest drivers. However I get slightly lower performance with 20.1.3 and 20.2.1 compared to e.g. 19.x drivers for my RX 5700 cards. I do see others do not have this problem, so I wonder what they have done differently. 20.x drivers are also required for new RX 5600 Series.

It might be a phoenix miner issue as it looks much better in Claymore