I have the two step electric step that seems to bind up after 5-10 uses. I have to unscrew the cover and let the swing arm sort of pop loose, a very small movement, and it's ok again for another 5-10 uses. It appears as though each use lets it move a little bit farther out of sync until it finally binds up completely. I am unable to turn what appears to be the manual release, again because it is binding for some reason. Anyone have this experience before?