Empty group list in "Inherit settings from groups" [subgroup] when editing a usergroup with assigned subgroups

[FelHell]

Bug Report

Prerequisites

• Did you reproduce the problem on TYPO3 core master?
• Did you reproduce the problem on TYPO3 v10.4 LTS?
• Did you reproduce the problem on TYPO3 v9.5 LTS?

Description

If a backend usergroup has no assigned groups in "Allowed backend groups for maintenance" and a backend user of this usergroup creates a new backend usergroup and assigns a subgroup to it, this subgroup will be prefixed with "hidden" in the field "Inherit settings from groups" and the list "Available Items" will be empty.

Creating a new usergroup:

Editing the new usergroup:

As a workaround it's possible to remove all items from "Inherit settings from groups" and save the backend usergroup. Then the list of "Available Items" will be filled again.

Steps to Reproduce

1. Create new backend usergroups "Dummy", "Foo" and "Bar" without any permissions.
2. Create a new backend usergroup "User Administration" which is allowed the edit backend users and backend usergroups and leave all checkboxes of "Allowed backend groups for maintenance" unchecked.
3. Assign this backend usergroup to a backend user and switch to this user.
4. Open the module "User Admin" and create a new backend usergroup. Assign the group "Dummy" in the field "Inherit settings from groups" and save it.
5. Reopen the newly created backend usergroup.

Expected behavior: Editing the created backend usergroup will show the assigned subgroup and list all other available groups as well.

Actual behavior: Editing the created backend usergroup shows the selected usergroup with a prefix "hidden" and the list of "Available Items" is empty.

Versions

4.1.0