httpproxy hangs

Pretty much every day we wake up to no internet. The httpproxy service hangs on my UTM server. Other connectivity continues to function, but no proxy.

We are running UTM home, 9.004-34 on a i3 with 8 gigs of RAM. Intel nics.

I'm looking at various logs, but I don't see anything striking. Can anyone suggest a starting point?

Restarting the httpproxy on the server restores operation, for an unknown amount of time...