I have a field group rule set to “Menu Item is equal to Header Menu” (name of the menu location). Everything was working fine for a week or so, but now when I add a page or post to the menu and save it, the page/post turns into a custom link with nowhere to add a URL. Save again and it disappears altogether! if I add a custom link, it stays as is upon save.
I’ve narrowed this down to the field group by changing the menu location – everything works fine/as expected when the field group is not applied. Tried with the default theme, disabling all other plugins, etc. but still get the same behavior.