2006 Jeep Liberty with Overheat on Dashboard Temperature Gauge

I have a 2006 Jeep Liberty 2wd (V6-3.7L) that is showing an overheat on the temperature gauge on the dashboard. I replaced the radiator (which I noticed had pin hole leaks), the water pump, thermostat, and the temperature gauge sensor. The car is no longer running through coolant, but the temperature gauge on the dash still reads an overheat. I do not have any bubbling when the engine is cool, no white smoke, the fan turns on just fine, a/c and heater work, no visible leaks, equal heat from both rubber hoses to and from the radiator and fluid seems to be passing through them. There is also no smoke and no weird sounds from the engine. The overheat on the gauge comes after about 10 minutes of operation and happens whether I am driving on the highway or stopped at light.
The only thing that causes the temperature gauge to go down to normal is turning on the heater full blast.
Is this issue just a short in a wire somewhere? Should I start thinking head gasket? If yes to head gasket, should I use the “sealants” that are out on the market as a temporary fix?

I would think step number 1 is a pressure test of the system. Low pressure can cause the symptoms you describe. My easy test is to give the radiator hose a squeeze when cool, then when warm if it feels the same you have a pressure problem. Could be as simple as a radiator cap.