The problem is that you deleted the posts in phpMyAdmin. When you do this it becomes extremely difficult to delete the orphaned post meta values. The link I posted is to a plugin that’s supposed to be able to clean this up.
The only way short of this is to build your own SQL queries and run them through php. The steps involved are
- Query the database and get a list of all active post IDs
- Run a delete query on the _postmeta table WHERE post_id NOT IN (post id list)
The developer of ACF does not visit here much, this is a users helping users forum. If you want to get input from the developer then the best chance you have of that is submitting a new support ticket here https://support.advancedcustomfields.com/new-ticket/
