replaceTrack() called on a sender object from getSenders() on RTCPeerConnection does not work at receiver's end.

[anitoanto]

Issue is detailed in this stackoverflow post.
This works perfectly from the sender's end in a RTCPeerConnection connection. There is issue with the receiver's end even if the code on the both end is same.

[fippo]

I don't think this is a spec bug but that it also exists in Firefox now is concerning.
See https://bugs.chromium.org/p/chromium/issues/detail?id=1124292 for the chrome bug I filed a while ago. Maybe @henbos can investigate that one.

[henbos]

I suggest making some noise over at the browsers' issue trackers, perhaps https://bugs.chromium.org/p/chromium/issues/detail?id=1124292, closing this issue on the spec.