Tune changing is common . You will find in the morning when the air is dense the engine will run rich , then as the day goes on it runs lean . this is one thing you have to deal with the other is tuning from half tank to get a mean tank pressure.

I suggest filling it up, do a few hot laps and tune from half tank. then run the tank out to see it it leans out or sags in power , if it does then richen .

it will take a while to get the hang of tuning dynamics but be patient and learn, and i would advise against tuning to a temp , just tune for performance .