Can you try running each card in a different instance?
Edit your config file and only run card 0
Then edit it again, and run card 1
then card 2 and then card 3
You should have 4 windows.
I had the same problem with 2 cards, low hash rate when run together.
Then I decided to run one card on ETN and the other on XMR, both now get over 1900 when run by themselves.
Interested to know if it works for anyone else