Fix the bug and add functionality to the custom WordPress plugin

There is a WordPress plugin that was developed by different artists. This plugin allows you to additionally display information in custom Advanced Custom Fields (post object and taxonomy).

The plugin itself is located here - https://disk.yandex.ru/d/cMBnjlrRQFR6TA.

There are several tasks:

1. The plugin has this error - If I choose from 1 to 4 Post object or Taxonomy, then there are no problems.
If I select the 5th object, then after saving the 3rd object in place, it becomes the 5th object and the fields of the 5th object are added to the selected fields of the 3rd object.
If I select 6 objects, then 4 will remain after saving.
If I choose 7, then 5 will remain.

And you can see that such errors work separately for Post object and separately for Taxonomy, that is, if I specify 4 objects and 4 taxonomies in the plugin, then nothing will be deleted.

It is necessary to correct such a mistake.

2. Now the list of selected post object and taxonomy is displayed simply in blocks (see screenshot). You need to make it possible to add groups to which you can add objects and taxonomies. Nested groups, that is, a group in a group, do not need to be created.

3. Make it possible to change the order of objects/taxonomies, so that you can set your own order of the selected objects/taxonomies by holding down the left mouse button (or in another way).