After SU12 and latest GSX updates still issues of people not routing through jetway properly at KORD gate K10 and C21.
I tried it now at C21, using the default Asobo A320, and passengers work perfectly fine here, walking inside the jetway as expected.
A thing of note is that, on a large airport like KORD, which is likely the airport with most jetways in the world, it might take a while for data about all jetways to come in, and if you call GSX too quickly while it's still getting the data, the data won't be correct, leading to passengers walking in the air, because the jetway position hasn't been obtained from Simconnect yet.
This might be possibly aggravated A LOT, if your Simconnect is under stress because of too many objects in the scene, which is easy to reach on such large airport, especially if you use AI traffic products that adds hundreds of AI on their own.
This causes Simconnect to work incorrectly, returning erratic data, as explained here:
https://www.fsdreamteam.com/forum/index.php/topic,29576.15.html