@Garden_Dude, just checking in to see if you got Zone 9 to fire yet? The common terminals are shared between the left and right terminal blocks. There's no need to install a jumper between the two white terminals.
Great idea @JNotar! @Garden_Dude, did you try testing like this yet? If we can get Zone 9 to fire on another terminal, then we might have a defect in your wallmount. If Zone 9 doesn't fire on any terminals, then we need to troubleshoot the wire and/or solenoid.
Please keep us posted.