When I connect PBE to MSFS, the airplane sound changes and all bass is virtually eliminated.  It becomes very tinny, however the Voice in PBE is not affected.  Sound returns to normal once pushback is complete and the program automatically closes.  Is this how it is supposed to function?

We have no control over aircraft sound, and our sound system exists outside of MSFS.

You'd need check your audio hardware settings for that one.

Best,