Here3 GPS and Here+RTK not making my data more accurate

I have been doing tests with the Here3 GPS and Here+ RTK base, but not seeing any difference in the coordinates on multiple flights, whether using the RTK or not. I let the RTK run for about a half an hour, with an accuracy of 2m set. From what I’ve read on other forums and CubePilot documents, the rover (drone) can still achieve centimeter level accuracy relative to the base, even if the base is only at 2m accuracy. Can anybody explain how the RTK data actually corrects the position and makes my photos more accurate? Does Mission Planner have to be running while doing RTK flights? Any tips, tricks, workflows, or feedback would be much appreciated.