My H376 companionway hatch was free until I wound the rigging up to the necessary tension for sailing. I guess I pulled the two side guide rails together. Also it sticks when the sun has been on it so I partially open it and wait 2 minutes and then it goes okay. I guess these are made to such accuracy that even the slightest expansion or deck distortion causes them to be hard to open or close. Anyway I live with mine but you may decide to unscrew one of the guide rails and file the offending bit away. It should be obvious where it is binding. Just seems a lot of work for such small gain.