Jave you tried to switch BATC to a different 3D renderer?
I am not an expert, but maybe that will help?
By default BATC starts on DirectX. As MSFS is using DirectX as well and VR can be very demanding for the GPU maybe all DirectX channels are in use.
Maybe switching to OpenGL or Vulcan for BATC can help.
You have details how to do that in the release note.