What can cause refrigerant pressure to fluctuate back and forth while unit is running on cooling-mode?

Refrigerant pressure fluctuations in a cooling-mode unit can be caused by several factors, including a malfunctioning expansion valve, dirty evaporator coils, or low refrigerant levels due to leaks. Additionally, inconsistent airflow across the evaporator can lead to pressure changes, as can compressor issues or improper system sizing. Regular maintenance and inspections can help identify and resolve these issues to ensure stable refrigerant pressure.