GSX would not activate at that gate and I got a message stating the aircraft size was not appropriate for the gate. This may be a limitation of the sim, but is there a way to make GSX active in these situations?
This has been discussed so many times in the forum, and of course is explained in the manual ( Page 24, the explanation of the "Max allowed wingspan" parameter of the parking customization page ), so you can override in the parking customization page any setting in the scenery AFCAD. The small icon with the airplane will automatically adjust the parking to your airplane wingspan.
However, since KIAH it's an FSDT airport, we might have to adjust the AFCAD too, sometimes parking radius are set in a specific way to prevent interferences from nearby parkings too close together, which affect jetways. In any case, I checked all the parkings around C16 at KIAH, and it seems they still work correctly even after adjusting C16 radius to make it bigger, and others around it a bit smaller, which seems to be more correct.
If you reinstall KIAH or the Stand-Alone Addon Manager, and reply YES to the question about downloading the current AFCADs, you'll get the updated version, so no GSX customization would be required.