Thanks for the reply, Stephen.
A few hours after posting my original message, the problem went away again. I did not do anything to fix it. Currently, there doesn’t seem to be a problem, both the “em” and “strong” tags show text as expected. I’ve never seen this issue before. I’d like to know what’s causing it.
The page in question is here
https://margotgalt.com/books/
The site is work in progress.
One thing I have not tried yet is loading the page on a different computer when the problem occurs.
