After some more logging, I see that kernel connect() - failed necp_set_socket_domain_attributes Shows up even on success in some cases. Haven't seen kernel ALF, old data swfs_pid_entry <private>, updaterules_msg <private>, updaterules_state <private> on success

Was there ever a solution to this found? I'm seeing this same error, both using BSD sockets and using NWConnection. (65 - no route to host for BSD sockets, 50 - network is down for NWConnection) The tunnel remote address, the server address in the config, and the address to which I'm connecting all match. I'm connecting via IP address, not by hostname.

Thanks Jason. I'll pass this on to the customer. Our app has been on the store for years, and this is the first time we've ever heard about someone running into this, but they've got the screenshots to prove it. It sounds like it's something our customer should be raising an issue about.

Looks like it was related to Microsoft Defender. Not sure exactly what was causing the problem, but removing MS Defender completely caused the issue to go away.