I have now completed a complete reinstall of P3D and then the bus. Initially all went well and I thought it was working OK. I did a flight from a default airfield and all went OK. So then I reinstalled GSX and UK2000 Heathrow and tried a flight this morning.
Now we are almost back to square one.
If I try to anything outside of the bus it freezes. For example any interaction with GSX, any interaction with ACARS, moving from full screen to windowed view, anything at all seems to freeze the bus. I disabled GSX and it seemed OK, but then clicked on the ACARS to start a flight and it froze.
So I restarted the Sim, loaded the bus at a different airport, started GSX and all was well, but then started ACARS and as soon as I clocked on the out of window App, the airbus froze. It seems to be the interraction with apps outside the sim.
It's basically unusable, and I am really frustrated because it seems like there's no way to fix it. I've done literally everything by the letter of the instructions for a clean reinstall!