My 2012 RAM suddenly lost the air conditioning one day. Went to work in the morning air nice and cold, came out in the afternoon and no air. Bought a can of the refill with gauge and it would not take it, showed over charge. A couple days later after I got a gauge set it showed the same pressure on high side as low side. Opened the valve to see if there was any Freon in the system and no pressure in the system. Ended up being the compressor had a leak. I replaced the compressor, vacuumed down the system, and fill it with Freon and is working fine now.
Any vehicle can leak down after a couple years, just like your home A/C it needs checked every so often.