Site to Site VPN with Sonicwall, GPO not working, DNS goofiness.

Hello,
I apologize in advance for any facepalms this post may cause. I'm out of my element a bit and networking is not my strong point. I am setting up a site-to-site VPN at a client location with a Sonicwall TZ500 at the hub location and Sonicwall TZ300 at the remote location. The remote location has no servers and is just client PCs. The hub location has one server as the Domain Controller, AD, DNS, etc. All locations are using a cloud-based content filter. At the hub location the DNS resolves internally first and the server has forwarders to send to the external cloud filter. I had to set the remote location to have the cloud filter first and hub second for DNS because otherwise it was sending all traffic through the hub office. This would be "fine" and works ok except now Group Policy is failing and claims it can't contact the DC. I can ping the DC, I checked/changed the MTU. I tried to do split DNS Proxy in the Sonicwall but it didn't seem to work. Anyone know any settings that i may not have checked yet?