The problem is caused by the fact the atc_id in the aircraft.cfg is G-FENX, while the one from Simconnect is D-AEWQ, but GSX gives an higher priority to the one in the aircraft.cfg, so it looks for this file:
[00:00:39.500] Airframe-specific GSX-G-FENX.CFG not found
We set the aircraft.cfg with an highest priority, because if you change the callsign in the sim (and maybe forgot you ever changed it), it would keep using the same airframe no matter which airplane you loaded, and this used to confuse users that assumed it was a GSX bug, so we reversed the priority to prevent the custom callsign to take over.
The issue is, with modular aircraft, it might make sense to use Simconnect by preference instead, with the obvious caveats that if you change the callsign, the profile wouldn't work anymore.