Air will not blow cold if I use heater then go back to air

About a week ago I got in my car and switched the air on and it was not blowing cold. I just had the compressor changed in August. After running errands, stopping and turning car off at three different locations in a twenty to thirty minute span. The air suddenly started working again and had been fine ever since. This morning I turned the temperature dial to a little past the middle and when I went to lunch I turned the air on and it would not come on. I was only gone for seven minutes so as of now I don not know if the air will come back on yet until I get off work. Over the years I noticed this has happened briefly a couple of times and was not a consistent issue (I live in Louisiana so going from hot to cold is common). Please let me know what you think this could be. Thank you!