We just got of off our 3rd DCL cruise (the wonder on Alaska). It was an amazing trip with one minor annoyance that I had not experienced or heard before. After our last breakfast while waiting to be cleared to disembark we tried several of the public bathrooms and none of them would flush. This made for a rather unpleasant experience and we decided to "hold it" until we got off the boat. Is this normal? We tried several floors.