It sounds like the condensor is freezing over.
Here are couple of things to consider,
1. High humidity levels will cause water vapor to freeze on the condensors surface , thus reducing the ability for air to move across the fins,,,turning the system off allows the ice to thaw and melt, thus restoring the airs ability to move over the fins,,until the condition repeats itself.
2. Setting the system to re-circulate and to a slower fan speed will enable two things :
Since the re-circulated air has a lower vapor or humidity level, there is less water in the cabin air that can freeze on the condensors fins. As an a / c system operates, it extracts water vapor from the air, thus drying the air, the water that is extracted, drains from the car and forms the pool of water on the ground below the car.
Air that flows over a cool surface will cause that surface to get colder and will enable ice to form faster.
The other area to consider is the Expansion Valve and the Sensor Bulb.
Not withstanding an explanation of structure and operation it is suffice to say that a faulty apparatus would cause the freezing and thaw rates to be disrupted and will cause erratic operation.