There's a couple guys on here who are knowledgeable regarding specific AC units.
It would be best if you post make and model of tthe AC unit. Also whether it is ducted system or not.
In general what you want to do is get airflow up. Make sure filters are clean and there is no obstruction to airflow. Use highest fan speed. Insure there is no cold air recirculating directly into the inlet. There may be sensors misplaced or not functioning. But this is an area for one of the experts.
The one thing I don't think is likely is loss of refrigerant.