webrtc.ConfigureNack() only wires up the NACK RTCP interceptor. pion still needs an explicit RTX codec registered per media codec before it can answer a publisher's retransmission offer with one, so incomingVideoCodecs having none means NACK-triggered retransmission can never actually happen for incoming video, no matter what the publisher offers. Fixes #5678 --------- Co-authored-by: aler9 <46489434+aler9@users.noreply.github.com>