Trouble shooting Ice on Evaporator and warm refridge

Brand: Kenmore
Model Number: 25354623403 Side By Side
Main Symptom: Evaporator is Icing and Refrigerator side is warmer than normal
What happens & when:

Error Code (if any):
Parts or tests already tried: I replaced the defrost thermostat and the evaporator fan motor
Photos / video link:

Is the evaporator icing up along the entire evaporator or is it only in a specific section? Also, what temperature is the freezer when measured checked by leaving a thermometer in between two bags of veggies or other items for about 20 minutes?

The entire evaporator is icing up. The fan is surging as well. I’m not near the fridge to measure temperature.

The defrost heater would need to be tested for resistance when the appliance power cord is unplugged. It should measure 30 Ohms of resistance, plus or minus 2 Ohms. If it does not, the heater would need to be replaced. If it measures good, the adaptive defrost control is the cause of failure. Here are links to each part.

Defrost Heater- 5303918255 Defrost Heater Kit (Freezer Evaporator) | Genuine Frigidaire OEM In Stock

Adaptive Defrost Control (part is discontinued)- 5303918476 Adaptive Defrost Control Board | Genuine Frigidaire OEM In Stock