About your second post. It’s not the sensor that is self-heating. The ESP itself is getting warm and the sensor is located right next to it inside the same casing.
I’m not sure if the ESP heats the air in the casing. Or if it conducts the heat through the same plastic they are both glued to. But either way: ESP on for too long ==> sensor gives temperature spike.
I know, it’s a bad design. When I made it, I underestimated how quickly and how much the ESP heats up.
I actually made a “how not to make a temp sensor” topic after I built it. =p