[pas.plugins.ldap] Unable to list users

Just switched from plone.app.ldap to pas.plugins.ldap on Plone 5.2 for migrated site. Short story: users from LDAP do not show up in the Plone user management UI.

Plone LDAP settings:

LDAP schema:

Looking at the query in base.py of node.ext.ldap: all queries are like with a specific uid when rendering the users management UI:

ou=resource,dc=contacts,dc=global (&(objectClass=inetOrgPerson)(uid=testsite)) []

The query supposed to list all users would be:

(objectClass=inetOrgPerson))

but not

(&(objectClass=inetOrgPerson)(uid=testsite))

Yesterday I configured pas.plugins.ldap successfully in a similar setup and it worked. So I suppose a configuration problem. That said, I never list all users in management UI but use the many users options and search for specific users in the UI. Since wildcard search is working fine this is a good option. Anyway, it should list the users.