AirPods Vent

How can I tell if the vent is clogged? One of the AirPods feels like an earplug. When I take it out of my ear, the tip turns inside out, which leads me to believe that the pressure isn’t equalizing correctly. The medium and large tips worked fine initially, and the small one is too small to make a seal. The small tip is too small to make a seal.

Is there some sort of diagram that shows how the vent is supposed to work?