Box temperature is always 3 degrees higher than setpoint

Hello, I have a 2013 Carrier 2500a and I’m having the same issue it’s about 3 degrees difference from what I set it which is a really big deal for me because I only haul produce and strawberry season just kicked in and they want the temp rite at 33 but it only gets to 36 so I set it for 32 but it comes down to 35 but if I set for 31 it it will actually bring it to 31 or even 30 which is too cold for strawberry, this is really frustrating me

 

Hello, I have 2013 carrier 2500a with the same exact problem that is always 3 degrees higher that what I actually set it for and since I only haul produce it’s a pretty big deal for me because when I load strawberries they are very strict and if the temp is not rite they will call me because they are tracking on it, where you able to fix the issue?