Seat position control unit on side of Passenger seat

The seat control adjustment unit on the passenger side disengages from the seat and "leafs out" on the top when one who is somewhat weighty (say 250+ lbs) exits the seat by shifting his weight and sitting sideways to get out of the car. Once the person exits the seat, I can push the unit back in and hear a "snap" that then puts the unit back in place. However, once the passenger goes through the same exiting motion, the unit pops off on the top again. Apparently pressing down on the seat when exiting causes the upper part of the unit to leaf out about 1-3 inches. What is the formal name of this seat adjustment control unit? Are there two snaps that keep the unit in place if an overweight person shifts his weight to exit the seat? Is there any recommended "fix" to keep the seat adjustment unit snapped in place when such a person exits the car?