One thing I thought I’d clarify.
It may not be in all cases for me that the Pi loses it’s wifi connection. Up until now, when the web interface becomes unavailable, I’ve assumed the wifi went to sleep.
I was just checking on the unit, and came to notice that the web interface seems to go out to lunch, and rejects the HTTP requests.
But the Pi is still available over the network and one can shell into the unit, even though browser access attempts on 8080 are rejected.
It does seem to at least anecdotally backup Tony’s opinion that the issue is related to the webserver.