Water leak from air manifold, 2004 Imperial

[ben94122]

Hi, I have a 2004 Imperial (or Monarch? both brands are on the unit) that I'm putting back into service after draining it for the winter. It worked well for a few hours, but now leaks quite a bit (about a gallon per minute) from the top of the manifold pictured. I'm new to this, and just guessing, so hear me out: This manifold connects to an air inlet on the top of the spa. It has hoses to each jet, and there is also a separate water hose to each jet. I'm guessing that it is an air intake manifold, with air entrained into each jet via venturi effect? If so, there may be a check valve at one of the jets that got damaged and is now leaking water back into the air manifold? Do I unplug the hoses, find the leaking one, and replace or repair the jet it goes to?
My sister-in-law has the same hot tub and has occasional leaking when a jet gets clogged by debris; she cleans the jet and the leak resolves. I'm assuming that it may be a similar issue. Can I just plug the whole manifold, not have entrained air, and avoid future leak problems?
Photos attached of control panel for identification, manifold in question, and a top view of the air inlet with the inlet valve removed.
Thanks in advance for your attention.

 

[ben94122]

So, for anyone who may find this post in the future--the problem is solved. It was indeed several clogged jets. Rather than air going from the manifold to the jet, the clog in the jet was forcing water back into the air manifold and out through the pictured hole. I replaced the clogged jet inserts and solved the problem. The clue was that there was no entrained air in any of the jets on that pump system, because the water from the clogged jets was filling the manifold and getting sucked into the other jets, so the venturi effect was entraining water rather than air into the jets that weren't clogged. There are no check valves in spa jet inserts or jet housings. This video was very helpful: