Crash when quitting packaged Rift build - OculusAvatarModule:ShutdownModule.

Our game does not quit cleanly when I call QuitGame.  I get a crash dump.  The stack trace says that it crashes in OculusAvatarModule::ShutdownModule(), called by UnloadModule.

Anyone know what would cause that or how I can prevent it?  I'm on Unreal 4.23.1 and using ovr_platform_sdk 12.0.0 I believe.
Thanks!