The top arm won't spin. I took apart the bottom water fine filter assembly and cleaned it as it had water solids build up from hard water. There appears to be plenty of pressure coming from the pump. As a test I moved the upper conduit spray assembly out of the way to hear for water hitting the front inside door and it noticeably does. I replaced the upper arm earlier. There doesn't appear to be any kind of o-ring seal on the conduit arm that slides into the funnel looking end.

Is there some other kind of seal associated with this conduit spray assembly that could be causing the water pressure to bypass the arm?