Might try moving the temp. slider up and down a few times, assuming you are talking about the 451 model. Also check the temperature switch located on the plenum located towards the center just above the passenger side footwell (right side of car). Check the connector. Sometimes they get loose.
The AC in the 451 smarts is not a climate control auto system. In my 2013, from new, I often had to set the temp well below the usual and expected temp number In hotter weather. That being said, there my still be another cause for your problem.