This is most likely caused by some mojo messages taking a long time to run (submit will wait for GPU process to finish processing draw commands, and getVsync will call WaitGetPoses).

My theory is that mojo will continue processing messages as long as the message queue is not empty, so we can get into a state where the message queue is never empty while presenting.

The fix will likely be to move slow work to posted messages instead of directly in the mojo callback.

Removing Internals>VR component and assigning to Internals>XR