That muffled hearing, stuffy sensation, and slight pain after landing is incredibly common. It happens because the air pressure in the cabin changes faster than your Eustachian tubes (the narrow passages connecting your middle ear to the back of your throat) can equalize. The result is a vacuum effect where your eardrum gets sucked inward.
Most cases resolve on their own within a few hours or days, but here is a step-by-step guide to speed up the process, ranked from simple to more advanced. Do these as soon as you notice the blockage, ideally while still on the plane or just after deplaning. how to unblock ears after a flight