We are aware of some door interaction issues with third-party liveries that looks to stem from livery artists using a different format in the Title= entry of the aircraft.cfg compared to our own liveries. If the Title= line does not include the door variant, then the correct door logic will not load in the simulator.
We're investigating this on our side to see if there's anything else we can do to detect which variant it loaded in the simulator, but for now, the quickest solution would be for livery artists to update the aircraft.cfg Title= entry so that it is in the format of:
[Aircraft Type] | [Pax Door Type] | [Cargo Door Type] | [Airline]
Mark - Just Flight