The jetway (in GSX) always will move to L1 (most front door) of our PMDG 777 and GSX asks us subsequently (of course) to open L1.
This has been discussed several times on the forum: the solution is to exchange the doors using the GSX configuration editor:
http://www.fsdreamteam.com/forum/index.php/topic,9092.msg72850.html#msg72850Note that, as the previous poster said, this will affect ONLY what "request" you'll see from GSX, before starting the boarding/deboarding procedure, since GSX doesn't have any control over standard FSX jetways, which will always go to the main passenger door, as defined in the [Exits] section of the aircraft.cfg.
This changes if the scenery use SODE, so you can CONTROL from the GSX menu, which jetway will go to which door. But even in this case, it won't change what door GSX is waiting for, in order to start the boarding/deboarding procedure.
Basically, the jetways are one entirely separate thing (regardless if they are default or SODE), and the door GSX expects to be opened before starting boarding/deboarding, is another thing.