Issue resolved.
It seems with these two modules it was some kind of conflict with the VR hand controllers.
The controllers themselves were not bound to anything, but if I switched them off the problem went away. So after a bit of testing I found that if I disabled the hand controllers in each of the affected module's control bindings menu, this issue went away but I was still able to use the controllers in game.
Major Corvus's post in Unable to get authorization for DCS after the latest update. was marked as the answer