Any thoughts why 2 of my 6 jets are not blowing any air? I am running a 2HP pump that is dedicated to the jets. No blower. 4 of my jets work great but 2 of them do not blow air.

Looking at my constuction photos (below) I see the 2 jets that do not blow air (red arrows) elbow up from the main line, while the 4 jets (blue arrows) that do work all elbow down. Any thoughts? What can I do to fix this?