Yes. In my experience (I do a lot of multiplayer flying) turning on the generic models does nothing to help the stuttering (although it seems logical that it should.)
The only solution we have found is either to turn multiplayer off or, when in a multiplayer flight, insist that everyone use a standard livery.
In your case is it possible that a player nearby is also using one of those aircraft but are using one of their own custom liveries that you don’t own?