child loses parent?

This doesn’t feel like a theme problem to me, but it involves the theme and I have no idea where else to start.

I installed WP a few days ago. I made a child theme to modify fonts and a few colors — no other changes at this point.

Now the page seems to look good sometimes, and look bad sometimes. It seems to switch at random — at first I thought something was wrong with my style.css and that there was a delay due to caching after I uploaded the changes, but now it’s obviously doing this all by its lonesome.

I’m not sure, but it seems like sometimes it fails to import the parent style.css. How this could happen intermittently, I have no idea, so I’m leaving this as “seems like”.

When I switch to the original twentysixteen theme, I don’t see this. I do see it in both Firefox and Chrome, so I don’t think it’s a browser problem. (I’m running Windows Vista, Firefox 44.0.2, Chrome 48.0.2564.116 m. FF and Chrome are up to date.) The web site is hosted on Apis Networks, which I have found totally reliable, though what do I know …

Any ideas on what’s going on, or suggestions of what to try next?

Edward