ok, i quit msfs2020, deleted the content.xml file from my flight sim folder (C:\Users\My User\AppData\Local\Packages\Microsoft.FlightSimulator_xxxx\LocalCache) and now the VDSGs work.
It didn't stop the jetway from 516 trying to connect when i was parked on stand 515 though.
Also, when parking on stand 515 the jetway is 'stowed' in the way of the VDSG of that gate so you can't see it when parking on the stand, could it be moved a little?
Thanks,
Jamie 🙂