Plug ins and in group and effect channel do not work


I have a strange problem. I just updated to 5.1.1 and now I cannot use Plug ins in 5.1 group or surround channels anymore. Although a signal is running through the channel an gets to the output just right, the plug ins don’t seem to to get this signal. They behave as if they are bypassed. Did anyone have this problem or know a solution?

Best wishes,