LDAP mit HCL Domino Server, Error displayname not set

i have as LDAP Server an HCL Domino Server.
I have make the configuration an here is all OK.
But when i log in an user, i become the error the the the user has no displayname set.

LDAP Login: Could not get user object for DN cn=test pws_test,o=test-frenz. Maybe the LDAP entry has no set display name attribute?

With the softerra ldap browser i see the displayname with “test pws_test/test-frenz”
can Nextcloud not work with an displayname withe the / sign?

i had the same problem last week.
After some detailed research I found out that Nextcloud tries to find a UUID for the user with the following attributes: entryuuid, nsuniqueid, objectguid, guid and ipauniqueid.
Since none of these attributes are included in the Domino standard, the error message “Could not get user object for DN …” appears in the log.
After defining an “existing” unique identifier attribute in the Ldap configuration (“Expert - Override UUID detection - UUID Attribute for Users") it now works for me. (I used “uid” even if that is not entirely correct)
Nextcloud 20.0.7
CentOS 9/7/2009
Best regards,