Atwood heat pump problems

[Rjha11]

Bought new FR3 with an attwood heat pump ac. The temperature on the thermostat jumps 10 degrees in 2 minutes and shuts the unit off. The fan then comes on every 2 minutes then compressor starts again for only 2 to 3 minutes. The coach temp is 68 but the unit thinks it's 78. Attwood said this is normal so won't pay for troubleshooting under warranty. Anyone else have this issue?

 

[Crockett]

pop the air filter off the grill and see if there is a divider between the return air and intake air or not. there should be a partition between grill and upper unit, half way back. thought maybe the sensor for temp may be on the upper board and not the thermostat.