You’ve got a heck of a mess on your hands.
The first thing that you need to do is to figure out why you can’t edit these extra field group. These field groups are either located in code or they are located in the theme in the acf-json folder. You need to search your site code for calls to acf_add_local_field_group to see what’s in the code. If you have a folder in your theme “acf-json” you can try renaming that and see if that clears anything up.
Beyond this, if it were me I’d start looking at field groups and their location rules and start making them as inactive to see if I could get rid of them that way.
Hovering over the field groups should give you the post ID of the field group, for example ..../wp-admin/post.php?post=989&action=edit in this case the post ID is 989. Groups that were added later will have higher post ID values. I’d try deactivating the newer copies first.
Basically you have a lot of work ahead of you and most of it will be guessing, trial and error, until you can eliminate what you don’t need.
