The only suggestion I would have, knowing that you've replaced all the inner parts and pods, (otherwise, I'd say the A-frame or pods), would be to make sure there is enough suction through the cleaner. If you have a separate cleaner line, close the main drain valve and close the skimmer valve halfway and have the cleaner valve all the way open. Make sure filter is clean and the system has plenty of flow. More suction on the cleaner will make it work better. You can look at this article that explains how the valves should be set.