You might do a search on "recumbent butt" on the internet. Some folks get similar symptons to what you described from riding recumbents. I believe that it is most often associated with more upright sitting positions, but it seems to vary by individual. Hopefully, you can find a bike shop that will let you take a long test ride not just around the parking lot. I have gotten "recumbent butt" on both my Rans Stratus and my Greenspeed GTO but only on rare occasion. I think that it helps me to be off the bike/trike and stretch every 10-15 miles.

Regards,

Gary