The only things I know of that would cause the fields to be different between the ACF field group edit page and how the field group is shown when editing is that the field group on the edit page is
1) Being loaded by a JSON file this is not being updated and this could be from an acf-json folder anywhere in the theme, child theme or a plugin.
2) The field group is being altered by a filter in some way, I think this would be rare.
3) The field group is being created in PHP before being loaded from the DB. This one is least likely, but possible.
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