Okay, I'll be recording the netstat -anL minutely. Before your reply, I'd jumped the gun and uninstalled Little Snitch, so I guess my first testing period will be without Little Snitch in the mix. I've turned off Remote DVR. Unfortunately, we won't be watching any TV this weekend, so we won't be exercising channels in the usual way until Monday, although I can leave an Apple TV client playing continuously. Also installed v2022.08.26.2245 with improved macOS diagnostics.
Okay, @thully's at 19 -- definitely on to something with this! And no Little Snitch, so that's probably not a root cause.
I can maybe add a WAN port forward from :8089 to :58089 and see if any external traffic is causing the unaccepted packet increments -- I noticed @thully had some external Censys traffic in the hours before his last hang -- I wonder if they're doing some kind of error response fingerprinting involving partial packets. -- oh, 58089 is localhost only. I can't do that. Oh well.
@thully : Yes, you're exactly right, turning off "Remote DVR" shuts off the NATPMP port forwarding in your Airport Time Machine to channels, so external traffic won't reach Channel's DVR. Although, you won't be able to connect remotely, of course, with that turned off, in case you're traveling.