2015 Volvo 670 AC problem

I've been driving 12 years and it seems like I've never had an AC system that has always run perfectly. The current issue is it will seem like it's working okay but as I'm driving along it blows less and less powerful. I turn off air circulation and then it will possibly start blowing harder sometimes I will turn the AC off with the fans all the way up and it will again start blowing harder at which point I turn AC back on. During the night the AC blows less and less both in the cab and the bunk until it's hardly blowing at all but you still feel cold air. The blowers are fine and the cab one was replaced about a week ago.

 

So you think it's either not enough magic gas or too much?... Should I pull into a truck stop and have them do a leak test and see how much Freon I have? This truck is had ####loads of AC work done on it over the last year over $2,000 and still not working right

 

Okay I'll test for leakage. The bunk will have the same problem.. I woke up suddenly and it was hot as hell but then I cranked the bunk fans to full and after a few minutes it was blowing hard and cold, when I went to bed it was on low and blowing soft and cold and fine. I went into the front bunk and it was #### hot I had to turn off circulation and crank it and after a couple minutes it started blowing cold.