Hi. You may wish to tell us the year, make, and model car. And check and report if your maintenance/engine light is on.
My 2008 Saturn stopped cooling even thought everything was testing good and I had fresh refrigerant.
There was an unrelated Error code which I kept ignoring, but it was saying something to the effect that "expected engine temp not being met "
I just kept an eye on the coolant temp and everything was fine. 190 as usual. For months.
I finally replaced my thermostat and temp sensor, simply to remove the "check engine" nag alert. A day later I noticed the AC had returned to cooling like a champ, as well !
Woo Hoo! A two-fer !
Apparently the computer did not understand something with coolant (radiator) temp sensor reading. So it was shutting the AC down because it did not want the engine to overheat.
Now I know to watch for that. Just the weirdest thing.