Despite following other posts regarding this same issue, I am unable to see the jetways connected to the terminal building at KORDv2 in P3dv5.3.
The GSX scenery customization page gave you the hint about what the problem is, which of course doesn't have anything to do with GSX or KORD, that's why you can't fix it by uninstalling/reinstalling GSX or FSDT KORD.
When the GSX scenery customization page says a parking spot has a "SODE XML Jetway", it means the Jetway has been added by means of an EXTERNAL SODE XML file, which is the case of 3rd party sceneries that added jetways to their sceneries through SODE, not using GSX.
All FSDT sceneries of course use SODE/GSX Jetways, not just SODE jetways so, on a clean installation, GSX won't say you have a SODE XML jetway, it will read just as a jetway, and you'll be allowed to edit it too. SODE XML jetways coming from other sceneries are not editable with GSX. You could replace those jetways with GSX, but you'll have to manually remove their SODE XML definition first, something GSX won't obviously do automatically, both because it's wrong to remove files belonging to other products, but also because SODE XML definitions might also include *other* objects needed for that scenery.
The reason why you have an external SODE XML file for KORD, it's because you must have previous installed Drzewiecki Design's version of KORD, which uses SODE XML jetways and, for some reason, either you uninstalled in the wrong way or the scenery uninstaller didn't remove the SODE files so, even if you don't have the scenery anymore, you still have the jeways, and they are preventing GSX to show the FSDT ones, because GSX always gives priority to the external SODE XML jetways, for the reasons explained above.
To fix the problem caused by the incomplete uninstall of Drzewiecki's KORD, go to this folder:
C:\ProgramData\12bPilot\SODE\SDX\DrzewieckiDesign
And remove the .SDX file for KORD there. Check also the XML folder if similar files exists as well, and remove anything related to KORD:
C:\ProgramData\12bPilot\SODE\XML\DrzewieckiDesign