I'm at wits end. In ground shasta pool with popups that won't turn. Popups come up zones change however some zones never go down so therefore they don't turn. Additionally some popups won't seat all the way down therefore they don't turn. Removed the manifold there are no broken glue in valves and all the gears are fine no broken teeth or anything. Can someone please help me troubleshoot what is going on? BTW pressure is perfect at 30 psi.