I use a plain old socket file descriptor. I suppose the CFSocket in the post title was misleading, I apologise. I don't ever send the data in the app, only receive it with recvfrom. Still, no prompt occurs and no data is received on iOS 14.

@Hydroplosion I submitted FB8699464 to track the issue.

It was indeed helpful, it's sad to see the shortcut gone. I filed FB8899247 to track the issue, still got no response though.