Well, here's the thing. Over 24 hours after moving the sensors to my RV from the truck. The pressure indicators never changed so unless the tires on the RV are EXACTLY the same tire for tire as my TV, then the display never updated.
And still hasn't. As far as I know, the display doesn't even know the sensors are 8 miles away in the storage lot.
Going to go back to storage lot and check/replace sensor batteries just to see what the results are. If nothing changes, these will be going back to Amazon. But even so, the display should do something besides flash and alarm the 2 rear tires (fronts are showing fine) if it loses contact. Can't find anywhere that says how often the display unit/sensors poll each other.