For those seeing this post and having a similar issue. I had to add in a search domain to the DNS entry under [Interface] on the client or client config file before sending it out
So instead of: DNS = ADDNSIP, 1.1.1.1
I made it this edit : DNS = ADDNSIP, 1.1.1.1, localdomain.tld
*ADDNS = Put in your internal dns server ipaddress
*localdomain.tld = Put in your local domain name