So the RTAC defaulted to 0 which is why I left it at that, and since I only had one tag it was obvious something was not right. After changing the register to 1 it acted a bit funny so I deleted the device and re-added.
The web based trend works, and the OH keeps its connection with the RTAC full time now!
Now the only issue I still see is I can’t select the checkbox in the openHistorian Manager to trend the tag as seen below. Even though now the light next to the device name is green, and its displaying values next to the tag name.