In Instant Config mode, you'll want to check 'auto-configure virtual controllers' = yes.
Go to Groups -> select group -> Instant Config tab -> expand Airwave -> AirWave Settings
If that's already set, then the next step is to make sure the retry limit hasn't already been hit.
1) still in Instant Config view
2) expand the VC list by hitting the plus in the Instant Config menu pane
- a column listing the VCs in the group should expand from the left side
3) select the VC who's in mismatched state
- keep the VC list open after selecting, as hiding the VC list will deselect the VC from focus
4) Staying in the Airwave menu, go to Mismatches
5) At the bottom of the mismatches should be an 'apply all'