I thought I read about this issue before in this forum but I can't seem to find the topic below.
I have an M20 (+ L2m, L3m and L3s) and specific inputs are currently dropping out.
In my practice room pysical mic inputs 7&8 (which take electronic drums stereo) will drop out after about 5-10min. There is not drop in output from the drum module but there is no input level coming in.
Examining further I can see the channel strip inputs for 1,2,7,8 all greyed out like there in no