The answer to 'why is my mini split not cooling' is that there could be several common causes, including low refrigerant levels, a blocked air filter, a faulty compressor, or issues with the thermostat or electrical components. Symptoms may include the unit not blowing cold air, the compressor not running, or the system short-cycling.
Some potential solutions include checking and replacing the air filter, adding more refrigerant if there is a leak, or troubleshooting the electrical and control components. However, for more complex issues, it's best to call in a professional HVAC technician who can properly diagnose and repair the problem.