Hi, I think I have this bug as well. Earlier I had figured out that disabling aggregation of CSS (I have disabled JS too, but maybe that was not necessary). I was going to start an issue, but this one seems to match. We first saw the problem on June 16th. We had updated autoptimize on the 15th. I tried troubleshooting on our staging site and I couldn’t reproduce the issue. So last week I tried again and it was fine at first, but then after an hour it was doing it again. A totally unstyled website. Today I was figuring that there was some conflict with wp-super-cache and had come looking here for ideas.
Let me know if you need any info or what not.
Thanks!