I have also found that to be the case sometimes.
If you wait until you start feeling the pressure to adjust the bladders, it's too late. What I've found was approximately every half hour change the settings whether you need to or not. That way it heads off any pressure build up in one spot.
Better yet when you stop for gas or to eat, walk around a little and (without being seen ) massage the tush a little to get the feelings/blood circulating again. ThumbUp
I know a massage seat as you drive the Trike!!