I have been using Ashampoo for the last few weeks and an older version of Sygate before that. I'm sure I was having the problem while still using Sygate, but at the time was running scans now and then late at night, so the problem took care of itself when I shutdown afterwards.
I tried going to Comodo, but even though I'm fairly technical, I guess I'm not smart enough to handle it, because I can't even get connected to my ISP when I try to use it and it gives no indication what the problem might be, or even that there is a problem.
I saw the recommendation to try the beta, but wondered about stability. I've learned over the years that "beta" has very different meaning to different developers. This might be a good time to try it, because in trying to fix the problem by reinstalling Avast I ended up installing it in a different folder, so I had remnants left in several folders, with my firewall rules pointing to the wrong place, so Avast updates aren't working for me now.