LDAP/Internal Users

Greetings Nextcloud Gurus,

I’ve recently integrated Nextcloud with our ActiveDirectory server for LDAP. Maybe I’ve misconfigured something, but I’m having a hard time seeing how “clean” this integration is. One item in particular I’ve noticed is that when using Talk, if I attempt to add another user to a conversation, the user search dialog will list both LDAP and internal users. Confluence has a similar issue, but fixing it there is a little less obtuse, and I haven’t been able to find an obvious method for correction.

Is there a way to force Nextcloud to recognize a difference of this sort?