Quick update.
After some more testing I think the MixedReality WebRTC implementation is the culprit (or it’s a WebRTC concept I’m missing). Meaning, it’s probably not mediasoup-related. I’d still like to keep this open, if that’s okay for you, to see if someone’s dealt with this case before or maybe has a better general understanding of the matter and can point me to the source of the problem. Unfortunately, the MR WebRTC package has just officially entered “Deprecation” a few days ago and is no longer maintained, so there’s no use trying to reach out on their platform.
It seems to be connected to the send direction. If I run the Vanilla test (direct p2p) and have a sendonly direction from the connection that creates the Offer and a recvonly counterpart, the issue is exactly the same. Video gets through fine, but Audio is missing. But it works if both sides have a sendrecv direction. From my understanding of the MR WebRTC code the Track should be attached as a mediaLine just fine (it’s also present in the SDP offer). If anyone’s got an understanding of what’s happening here, I’d greatly appreciate if you could point out what might cause this. 