Actually any time your using channels assigned to audio groups (not DCA) and those groups
are assigned to the LR mix you need to unassign those channels from the main LR mix.
If you don’t you will get some phase issues due to the slight routing path latency differences between a channel going to straight to the main LR mix and being routed
through a group assigned to the main LR mix when the two signals sum back together
at ever so slightly different times.
And yes you can hear it.