[Bug]: LDAP-Search not working

⚠️ 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

Dear Nextcloud team,
since the update to version 27, the search of users in the share dialog does not work anymore. Only local users are found. Users from LDAP are not found.

LLDAP is used as LDAP server.

Only this entry can be found in the Nextcloud log:
ldap_search(): Search: Other (e.g., implementation specific) error at /var/www/html/apps/user_ldap/lib/LDAP.php#307

LLDAP Log:
[error]: | Database error: Query Error: error returned from database: column reference "display_name" is ambiguous.

Steps to reproduce

Expected behavior

Users from the LDAP backend are found.

Installation method

Official All-in-One appliance

Nextcloud Server version

27

Operating system

Other

PHP engine version

PHP 8.2

Web server

Apache (supported)

Database engine version

PostgreSQL

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

Upgraded to a MAJOR version (ex. 22 to 23)

Are you using the Nextcloud Server Encryption module?

Encryption is Disabled

What user-backends are you using?

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

Configuration report

No response

List of activated Apps

No response

Nextcloud Signing status

No response

Nextcloud Logs

No response

Additional info

No response

Start at apps/user_ldap/lib/LDAP.php#307 and inspect the LDAP search that produces the reported error; compare it with the LLDAP log showing ambiguous display_name. Reproduce the share-dialog LDAP user search on Nextcloud 27 with LLDAP and PostgreSQL, then confirm LDAP-backed users are returned without the database error.