So I was talking with my brother-in-law and he said his truck was doing the same thing last year, hit the a/c button, engine RPM would drop, but no cold air. He had bought a can to charge the system and it told him the pressure was fine, so he didn't add anymore. He was at work talking to a guy that does a/c and he said to add more. My brother-in-law wasn't real sure about that, so the guy went out to his truck and even though the compressor would come on at first it would shut off. The guy started putting in more refrigerant and the compressor kicked back on and then the pressure dropped and he filled it to were it should be and the a/c worked fine. He said they put about 2 cans into the system.
I imagine this is what's going on with my system. So tomorrow I'll pull the panel behind the seats and watch the compressor. If it shuts off I'll go grab a couple of cans and do the same thing. Last winter my Boxster did sit outside instead of in the garage, so maybe that caused the system to leak?
https://www.autozone.com/a-c-charging-and-refrigerant/r134a-refrigerant/quest-r-134a-with-stop-leak-not-for-hybrid-vehicles-with-electrical-driven-compressors/233036_0_0