Please clarify if you are on a gate with a jetway because, as explained in several other posts, GSX doesn't handle L1 door anymore on gates with a jetway, because after a few updates ago, MSFS itself is doing that: it will open the main passenger exit when the jetway closes in, and it will close it when the jetway disconnects.
There's no way for us to prevent MSFS to do that and, because of this change, GSX now doesn't control the L1 door anymore, because if it did, it would conflict with the MSFS own handling.