2012 Sierra AC control issue

[Gmc12sierra]

I have a 2012 Sierra with the dual climate control. When the passenger side temp control is off the temp control works. If I turn the pass temp control it blows cold unless it’s at 90, 89 and below it’s ice cold. Any ideas? I was thinking it was the blend door ac or the ac control module. Also sometimes even with the passenger temp off it does the same thing, if I turn the ac off then back on it works.