Have you tried resetting the mix console?
(The little triangle pull down menu in the upper right corner of the console)
I have to do this about once a week.
Maybe search for “reset mixer” first as some here have said you need to
press “Alt” while resetting, but I’ve never had to do that.
Not sure what the difference is between using the “Alt” method and just
doing a plain reset either. No documentation.
Warning:
This will completely trash your mix so try it on a fresh project or “save as” first.