Contrymn

I have a 16 x 32 above ground pool with a 1 hp Hayward Power Flo Matrix pump. When I turn my Jandy valve to operate the Pool cleaner there is no suction at pool cleaner and the pump losses its prime. When I turn the Jandy valve in all other directions it works find. I replaced the O ring on pump basket still same problem no suction at pool cleaner and pump losses its prime. The pool cleaner is a Zodiac Ranger and I just installed a new diaphragm.