The Xfinity Discovery Hub "search the web" function is not working

The Xfinity Discovery Hub "search the web" function stopped working Saturday 3/1. I'm using Safari on a Mac. It was working, then suddenly stopped during my online session. I followed ALL of Apple's troubleshooting steps. I've tried using Xfinity's online tech support, and they were useless.

I've had a similar issue some time back on a different Mac, and it was an Xfinity issue.