I need help. I used to mine with Claymore 15, Blokchain driver  and RX570 nitro+. My speeds were 32.5 Mh/s and I switched to Phoenix miner but my speed is 31.5 and I cant change -mvddc value. If I put -mvddc it wont start mining just crashes. I can mine without that value but my power usage goes up a lot when compared to Claymore. I tried 20.8.1 drivers but only get 10 Mh/s and I can get it to work with -mvddc 900. Any ideas?