I cannot replicate the problem, GSX autostarts with MSFS 2024 normally with the latest Fenix update. I also tried the fuel automation, works normally as it always did.
GSX no longer downloads automatically refueling and the mass and balance on the EFB tablet are reset to 0 after 30 seconds
I need to clarify this, because there's seems to be a profound misunderstanding what GSX does or doesn't. It's very simple, in fact: GSX doesn't do anything. It never refuels the airplane, it never changes the payload, it never operates the Fenix EFB (or any other EFB for that matter).
What GSX does, is inform developers it needs something or it's doing something, like it wants a door to be opened/closed, or it has connected the fuel hose, but that's it, what happens (or doesn't happen) next, it's only happening (or not happening) completely inside the airplane own systems.
The one and only time GSX "touches" an airplane system, is when Pushing it. No other airplane systems are ever affected or handled by GSX in any phase of the service, except Pushback.