After 2 minutes, the hashrate dropped again, but still more than cuda 11.5

https://i.ibb.co/3kMjPCD/Screenshot-2022-01-20-at-19-56-35-W5-ethash-1-324-GH-s-Ed-Konst.png

with 13 cards you should get at least 1404 in the miner window on optimal settings. 108MHASH each. But perhaps you are running in powersaver mode.