I have 2 sites hosted with the same company. Both sites rely heavily on the Advanced Custom Fields (v18.104.22.168).
On one site all the ACF fields on the edit pages suddenly disappeared. It took me a while to realise that all the screen options relating to the ACF fields I created had 'unchecked'. When I turned them back on they appeared but one of the fields is supposed to be a WYSIWYG but instead just shows as a Text Area field. I check to make sure all the setting with ACF were correct, they were. When I went back to the edit page to see if the ACF field had changed to WYSIWYG all the options had again disappeared.
I turned off all the other plugins except for ACF just to make sure it wasn't a plugin causing the issue. It wasn't.
The other site which uses the same set of plugins works 100% fine. Both site WP installs and Plugins are fully up to date. Anyone got any idea why for one site the screen options aren't being remembered and the ACF field isn't showing as it should once I turn the screen options back on?