I remotely installed the 11.2 on my friends pc and is terrible if you disable dual mining, for example, during afternoon is blazing hot so usually turn off dual mining and when it turns dual mining off, is bad, had to reverse to v11 and this is my first time i reversed it. And to mention, 4 out of 8 gpus crashed after dag creation and only lowering the clock core a lot could make them to work again. So back to v11 on that pc and, @claymore you should investigate why updating the kernels brought such drawbacks.
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.