Whenever I add a WYSIWYG field, the options always return to default on save. This appears to have only started happening recently.
I had a large Flexible Content field group, so originally increased the php_max_vars and memory, but that didn’t solve it. So I created a new field group with a single WYSIWYG field (which had a random, unique fieldname) and that won’t update either.
This appears to be a new problem, and occurs on a blank WP install also.
Screenshot attached of the fields I’m referring to.