I'm using Unity Transport 1.4. I have an unreliable pipeline (NetworkPipeline.Null) and a reliable pipeline (ReliableSequencedPipelineStage) set up both on Server and Client. The unreliable pipeline works both ways, but it seems the reliable pipeline works only one way (Server to Client). I can send reliable messages over that pipeline and the Client receives those. The other way around I get a StatusCode.Success at the Client sending a message over the reliable pipeline but it never arrives at the Server. I couldn't really find anything relevant in the changelogs except for this in 2.0.0 exp 7: "Fixed issues with ReliableSequencePipelineStage that would, in rare circumstances, lead to failure to deliver a reliable packet." But it happens everytime all the time that the server doesn't receive the reliable message. Is this the same issue in 1.4.0? Edit: Updated to Unity Transport 2.0.2 and the issue is still there. It seems like it's pretty much impossible to debug on this end because there's essentially nothing exposed that could be debugged. The message just never arrives.