I saw something similar and then changed from "-asm 2" back to "-asm 1" and the single mining went back up where it should have been.
yeah it must be the asm, i'm using "-asm 2", thanks for that, will try "-asm 1" later.
I tried, like you said it works good however I can't understand why 4 gpu of 8, crash with these kernels v11.2 and not on the v11, same settings. I have to reduce dcri a lot and core clock down to work on those 4 gpus. Strange.