RO BH90 HOB Skimmer

I have tried setting up my skimmer according to the video on YouTube. And no matter what I do, I can't get the skimmer to fully function. In the chamber, there's only a few micro bubbles floating around. No swirling vortex like normal. Is something possibly clogged? What would it most likely be and how do I clean it? It hasn't produced any skimate for me in 5 days.