Cabin Pressurization leak bubbling outside the airplane.
Static leak allows cabin pressure in.
Ports not flat to airflow.
Shape and condition of sealant around ports
Bug in line.
SSDC curve different right to left.
Static lines not crossed.
Dent fwd of Static ports.
One ADC gets crazy when it gets cold.
Paint stripe edges on a fast airplane.
Turn buble mounted slightly crooked, causes pilots to trim the aircraft out of level. Affects static ports.