This was discussed many times on the forum, the airline code in the aircraft.cfg doesn't affect the ground operator, it would be wrong if it did, because you can't expect to have your home base operators following you everywhere in the world. Instead, the ground operator is related to the airport AND the airline codes of the PARKING. The manual and (more so) the PaintKit documentation, explain how the scoring system works.
So, it's just normal, and it's how GSX is supposed to work, if the operator selected doesn't match the livery your own airplane, it's you that must selected a parking where your airline is located, so the atc parking code of the parking spot will likely match your airplane livery, assuming the airport has the airline codes assigned correctly.
This clears up the first issue. What IS a problem, is the 2nd issue, the vehicles mis-matched between each other, which is not supposed to be happening, once an operator is selected, all vehicles must be of the same livery, the only possible reason why they aren't, is if there's no other choice, for example if the vehicle of the correct livery doesn't exists, but that's not normal, because surely a complete GSX installs has the complete vehicle set for all these companies.
Do you recall which operator was announced to service the airplane ?
