It is the Field_Key unfortunately.
I guess the newer versions of AFC has more random generation of the field_keys.
I guess I would like to have a “database upgrade”/”upgrade” or a “Fix duplicated field keys”-button/function to solve this.
Making a database-hack, and many manual steps to fix this does not seem like a solution that I would feel confident in. Even though I understand somewhat steps on how to achieve a fix.
There should be an internal check which could be viewed within the admin about notices/warnings.
I remember this as a problem earlier when importing/exporting ACF groups from places, or the need for duplicating etc etc.
I wish this could be added some more checks in current version as well, especially when it comes to upgrades and other things like that 😉
