No, I haven't tinkered with the cache here. I did notice it was happening to another site of mine, suggesting it was a problem with the server.  My last host was fine as far as speed goes, but I just wanted to go to a more economical option.  My current host was fine up until that glitch a couple of weeks ago.  Now, it seems to have worked itself out and I'm getting the speed that we had initially.  Let's hope it's permanently fixed.  🙂