[Bug]: Group selection persists between user creations and cannot be cleared in "New Account" dialog (Group Admin)

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github OR Nextcloud Community Forum (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

Hi Nextcloud team,
I’ve encountered a reproducible issue when creating new users as a Group Administrator that affects the group assignment functionality. Here's what happens:

Actual behavior

Selected groups cannot be removed once added.
Group selection persists between different "New account" dialog sessions.
Only logging out resets the form properly.

Thanks in advance for looking into it! Let me know if I can provide further info.

Best Regards

Steps to reproduce

1. Log in as a Group Administrator.
2. Open the "New account" dialog to create a new user.
3. Under "Member of the following groups", select one or more groups.
4. Try to remove a selected group by clicking the "X" next to it – nothing happens.
5. Close the dialog and reopen it to create another user.
6. The same groups are still preselected, and cannot be removed.
7. Even if you complete the creation of the first user, the next user will also have these groups preselected, and they remain unremovable.
8. The only way to reset the state is to log out and log back in.

Expected behavior

• Selected groups should be removable by clicking the "X".
  

• When closing the "New account" dialog, the form should be reset to default state.
  

• Group selection from a previous account should not persist into the next user creation.
  

Nextcloud Server version

30

Operating system

None

PHP engine version

None

Web server

None

Database engine version

None

Is this bug present after an update or on a fresh install?

None

Are you using the Nextcloud Server Encryption module?

None

What user-backends are you using?

• Default user-backend (database)
• LDAP/ Active Directory
• SSO - SAML
• Other

Configuration report

List of activated Apps

Nextcloud Signing status

Nextcloud Logs

Additional info

No response

No files, tests, or entry points are named. Start by reproducing the issue in the Group Administrator's New account dialog, then trace the group-selection state across closing and reopening the dialog. Done means selected groups can be removed and a newly opened dialog starts with no groups selected.