Multiple LDAP Server entries (&1 and &2) cover "&3:&4" as referral target

What causes this issue?

The ICM LDAP plug-in received a referral or search result reference, and
the LDAP server which generated it is not configured in LDAP server
customizing to implicitly trust all such objects.
Therefore, the combination of hostname and port was searched in the LDAP
server customizing with LDAP application type "Referral Target
(Whitelist)". During this process, multiple matching LDAP server entries
have been found.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

Ensure that only a single LDAP server entry of type "Referral Target
(Whitelist)" can be identified using the lookup rules (exact match wins,
non-exact matches are won by the entry with the longest host name
pattern).

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.