So you're suggesting that this might rather be an issue on their side?
Not necessarily, it might be any one of those issues:
- GSX being confused when controlled externally
OR
- Something in the specific FS Labs procedure you are supposed to follow you are not. But I can't help you here, because they constantly improve it, so I'm not 100% sure to be qualified to explain that or check if you did anything wrong.
OR
- A possible issue on FS Labs side.
But all of these assume this problem happens ONLY when GSX is controlled externally. Which is why I asked to try with an airplane that doesn't do that. Of course, as usual before replying, I tried it using a default airplane ( default A321 imported from FSX ), and Boarding completes normally with no issues I can see.
However, my test was made by assuming you used Boarding ( it seemed so ). It would be more thorough if you provided extra details about the EXACT sequence of operations you did in GSX and, for example, if you used Automatic services or not but again, all of this works in a very different way if GSX is controlled by the airplane, that's why before I can check anything, I need to know IF and HOW it happens ( assuming it does ), on a default airplane or a 3rd party plane that doesn't control GSX.
During these days, I made many tests with the PMDG 777, which surely doesn't control GSX, and couldn't notice any issues like the one you reported.