Is A/C working normally?

Theres absolutely no point worrying about cabin temperature .
All you can do is test the supply air out of the vent and like i said before it needs to be as close to 41 degrees as possible . You dont want it too much colder than that or you may have evap ice up issues .
But i agree if its above 50 degrees and wont get any colder , then its more than likely something is going on .
But you need to try it on a 70 degree day also and if its cycling on and off at temperature then but isnt cycling on a 100 degree day then it may just be the amount of heat entering the cab
ben