I'm seeing this same issue.
I just upgraded to CentOS 7.4.1708.
kernel 3.10.0-693.2.2.el7.x86_64
ncsvc -version
Version : 8.2
Release Version : 8.2-5-Build49363
Build Date/time : Aug 25 2016 16:19:10
The client connects just fine, and everything would appear normal. But nothing is actually getting sent out. DNS lookups fail, pinging known valid IPs fails, etc.
The workaround mentioned at the top seems to work for me. But I'd like to be updated on an official solution and a more permanent fix to the problem.