The newest driver is 20.12.1, I suggest you to update: https://www.amd.com/pt/support/graphics/amd-radeon-5600-series/amd-radeon-rx-5600-series/amd-radeon-rx-5600-xt
Update windows too, and with 5600XT you should do 39Mhs
I use this settings on Radeon Software:


With more power tools you can increase hashrate and efficiency, lowering the Core Voltage without need to biosmod: https://www.igorslab.de/morepowertool-amd-radeon-rx-5700-und-rx-5700-xt-tweaking-and-overclocking-software/

Use the newest Phoenix Miner too, it's important, because there's a lot of improvements: https://bitcointalk.org/index.php?topic=2647654.0