One day both sides were not blowing cold air. I noticed a lot of frost on the inside of the back side of the freezer. Turned off the fridge, cleaned the coils under the fridge with a brush and vacuumed it all out. The compressor was not turning on, probably due to all the dust causing the capacitor to overload.
Replaced the defrost thermostat, and capacitor at the same time as preventative maintenance. I think replacing the capacitor would have solved the issue, but I did both just in case. Parts were inexpensive and a fast fix. Highly recommend.