pump is good, but won't drain

My Frigidaire FDB345LFS0 won’t drain. I have isolated the pumps, #56 and # 60 on the parts list. They both work. The drain hose on the unit is not clogged. The sink drain is not clogged. It has randomly performed poorly over the last six months. One day when I opened the door, water was at the level of the hinges. What am I missing? Thanks for any help you can give.