We have a new Carrier furnace/AC & Touch & Go thermostat.

1) The AC keeps running past the setpoint but only shows the setpoint as Actual temp. Set=73 Actual=73 but real temp is 71. 1st repairman said it was normal to run 3 hours for 1 degree & be 2 degrees colder than setpoint & this is how new ac works. Told him I set U2 backlight to OFF & U4 program to NP. Still told me nothing wrong. 2nd repairman replaced thermostat & it worked. That was until I set the Advanced Settings U2 backlight to OFF, that makes the AC run on. So I turned the U2 backlight back to ON & now it stops at set temp. Why is the backlight controlling the AC shutoff? Hoping someone can figure this out before I call for the 3rd time because we are stuck with the backlight on.

2) The Actual Temp drops 1 degree when you go to start the AC. Actual=74 & I Set=73, then Actual drops to 73 immediately & doesn't click on. You then have to go to 72 to hear the click on & reset to 73. So now I click down 2 degrees to 72 to hear the click & bump up 1 degree back to 73.

Anyone have this problem?