Well-established website using Atahualpa theme.
After update to 3.8.2, editing any post or page, or adding a new one, immediately results with the dreaded
Connection lost. Saving has been disabled until you’re reconnected. We’re backing up this post in your browser, just in case.
message at the top of the edit page.
This site has been stable for well over a year, and even though we're getting that message, page/post edits & saves work flawlessly - hence the "likely false" in the title of this post.