System #2 was low on refrigerant. (TXV) Checked evap coil, blower fan, outdoor coil, and filter. Did a spot leak check on the system and didn’t get any hits. Customer agreed to add refrigerant (3lbs). Told the customer if this happens again we need to do a more in-depth leak check. Delta Temp is now 19.8° and refrigerant levels are within normal range.