I realize I am probably the only person in this forum with this problem but I mention it in case it is affecting anyone else.
I was looking into settings in my AdSense acct yesterday, setting up for a new domain and found that some ads had been disabled. No notice, if I hadn't been looking at the colors settings I would never know. The ads have been showing just fine, no idea how long they were "disabled". The reason: I had not configured any color for the visited links for custom search engines. I'm not using custom search engines.
Some of my ad configurations go back several years, I update the code when I add a new ad or make changes. I have no idea how long I had this disabled ad showing on my site without letting me know it was "disabled". It does explain some weirdness that wasn't making sense. Sneaky devils.