Success!!! Thank you to Kevin and Yann in particular along with others that added comments. A couple hours after I posted my last comment about not wanting to make multiple changes to resolve the problem, it stopped responding again. So I remoted into the server and added the two lines for AcceptFilter to the configuration and restarted Apache. Confirmed in the error log that the AcceptFilter directives were in place. I'm now getting close to 3 days without a failure. So it looks like that was the solution.
Thanks! Jim
