Upstream issue https://github.com/keycloak/keycloak/issues/10412. The problem is that there are three different commits/PR that are related to this change:

• https://github.com/keycloak/keycloak/pull/19352: The PR that fixed the `getAttributes` method in the LDAP part.
• https://github.com/keycloak/keycloak/pull/15929: Another related PR that fixed when teh LDAP attribute is deleted. This should be also added IMHO.
• https://github.com/keycloak/keycloak/pull/12168: The PR that fixed the issue originally in upstream although it's a bit unrelated and more a performance enhancement.

Don't know what I'm gonna to backport finally.