Let us know what you find. (If you find a way). One thing you may not have investigated, which is still on my list of "unknown territory worthy of investigation); is to look at the filedescriptors associated witht the socket. I wonder if you identified which filedescriptor is handling the socket data, then somehow test it for ( who knows what ?) to see if it's connected?. Maybe the POSIX module may have some clues for you?

The reason I mention it, is I was experimenting with a server, trying to restart it, without re-execing it, and there was some stale filedescriptors which needed closing manually with POSIX, before I could accept connections. It's pretty complex, with modules involved, but there is some control available to you way down at the "c-code' level. You can see what filedescriptors are open for the socket, with the "socklist" command.

Just a brainstorm.