Seems to happen only when sending on the listening side, not the client side.

I'm getting the same thing. Apart from the warning, things seem to work OK.

Just ran into this as well. Paradoxically, my Network Extension would provide internet connectivity, but because there is none, it cannot get started. Submitted as FB9049634.

@HPmax, I know it's a "bit" late, but this should work if you are using plain TCP (no TLS). You must send() with data=nil and a context that has .isFinal=true (such as .finalMessage).

Update: If you want to get "EOF"/half-close connections over TLS, you will have to implement a custom framing protocol. Apple (or at least Matt) states this is not a bug and works as expected (DTS 762944544). Implementing something like a "byte count server" (server receives arbitrary bytes, then upon end of stream, replies with a byte count) reliably is not possible using TLS & Network.framework.

2 years later still a problem, right?

Hi, No response on the Feedback yet. Also, tried to re-submit a TSI... Still a problem, and opened another Program Support ticket (101329668227). Any chance you can look at this, and I submit a TSI retroactively? :-) Jaka

Submitted as FB9016170

Matt, I submitted the report, ticket ID is FB9008451. Jaka

Matt, Have you seen the video above? Jaka

There is really something wrong with the system. See here for video: hXXps://paste.jaka.io/2021-02-11/TSI.mov Form says "Request Code-level Support". After submission it says "You will receive an email shortly with a follow-up number from Apple Developer Technical Support". And now I have a third open case where the poor Program Support guys cannot help me: 101319294793 101319947452 101320880570 - Man, are we off-topic to troubleshoot some completely unrelated issue now :-D