I have two evga 3060 cards.
mixing them with 3070 may not work.
Mine did work on windows 10. but i now run them on smos.
Gpus are like mother fucking unicorns.
mobos are cheap.
buy a second mobo and use it for the 3060 card.
erase all the drivers on the mobo and load ones for the 3070 and just run the 3070 on 1 board.
Good luck fixing it.
I`m really surprised. Did you try HiveOS/ RaveOS or minerstat? May be problem in smos? You say that windows mining is ok, so may be you need just to wait for smos update?
PS. Of course if you have an opportunity - the best way to move 3060 for another rig.