Nothing is wrong. Which driver are you using, and did you enable compute mode?
Used 19.2.2, and had 2000+Hs on 1.8.1 but 1100Hs with 1.8.2 then updted driver to 19.3.3. Same results, 1.8.2. hasing only the half of 1.8.1.
Compute mode is unavailable when you have got vega, you can change it with lower cards, like 580X. So stock driver, and HBCC off.