I run Xplane 11 and have recently started flying on the Vatsim network.
I use Xpilot
My problem is this:-
When flying my engine and environmental sounds drown out the voice of the controller and I have to keep asking to repeat.
I understand that to avoid this the aircraft sounds should be directed through speakers and ATC chat through headphones.
My problem is, I direct aircraft sounds through my speakers but as soon as I plug in my headphones (usb connection) it divers the aircraft sounds through the headphones.
Perhaps either have your headphones plugged in before you start the sim, or change the sim audio or Windows audio settings if something gets changed? Just guessing, but perhaps when you plug in your headphones, Windows is treating them as a default device, and your sim is set to default audio? If that is true, change the audio settings in your sim to the speaker (not default) (if XP allows you to do that – I don’t know, I don’t run XP, so this is generic advice).