Windows Video SDK session not starting, but no callbacks or error information

We have a existing, working integration of the iOS Video SDK, and we are now working on a Windows version. As far as I can tell, I have reproduced the same API calls and JWT token generation which work on iOS, but they don’t work on Windows.

Calling joinSession() returns a non-null pointer, however none of our delegate/listener callbacks are ever called, and isInSession() persistently returns false. So it is not connecting, but no error information is available.

I’m using SDK v1.3.1 in Windows 10.