NetBIOS and Windows Event Log Sources

I have a problem since we disabled NetBIOS over TCP/IP on all our network adapters.  My FAC can no longer connect to my GC's and so Fortinet SSO isn't working (Windows Event Log Sources won't connect).  I need to support firewall groups in my policies but without my FAC being able to enumerate users on my DC's that's a problem.  FAC relies on NetBIOS?  Isn't NetBIOS virtually deprecated by Microsoft these days?

I am talking to support, but was wondering if anyone has run into this limitation.  Don't want to re-enable NetBIOS just for FAC.