For the past couple of weeks or so, well, really since page experience report launched in late April in Google Search Console, there has been a bug with some sites over HTTPs. The error is "Insufficient HTTPS coverage on your site" and it is a known bug with the report that Google will fix.
Here is a screen shot of the error from @PeterMindenhall:
John Mueller confirmed this was a bug twice on Twitter, once on April 29th and the other time on May 7th. John said "It's a bug."
This can happen "if there are no URLs reported on," John explained. He added "then it's just that we don't have the data, and the UI incorrectly claims that the site is failing because of that."
John said "we're working on fixing that, sorry for the confusion!"
Here are more tweets on this:
Unfortunately there's a bug there in Search Console. When we we show "Failing / Insufficient HTTPS coverage" in the Page experience report, that can just mean we don't have the full data (instead of saying "not enough data" we incorrectly say "failing"). We're fixing it.
— 🍌 John 🍌 (@JohnMu) April 29, 2021
If your site is properly on https, then there's nothing you need to do.
— 🍌 John 🍌 (@JohnMu) April 29, 2021
It's a bug. If there are no URLs reported on, then it's just that we don't have the data, and the UI incorrectly claims that the site is failing because of that. We're working on fixing that, sorry for the confusion!
— 🍌 John 🍌 (@JohnMu) May 7, 2021
There are many complaints about this on the internet, so you are not alone.
Forum discussion at Twitter.
Update: August 4th, Google said this is now fixed.
