Eli your cup looks loose in the skimmer. I'll bet there are a million bubbles blowing past the bottom funnel of the collection cup. :mrgreen:
I saved your pics and edited them using Windows Paint. The red lines are the 2 pieces of plexiglass or lexan that you need to glue into your skimmer body to tighten up the fit.
First is your pic that I edited and the last are pics of my own refugium. You can see that I actually used 1 piece on the front side where the powerhead and intake tube enter the body. And I used 2 pieces to build up extra thickness on the left side of the fuge. This was 1/8th inch thick lexan. I just turned off the pump and let the fuge drain backwards into the tank. Then I dried the inside of the fuge with a towel. I used medium CA glue (super glue) on one side of the lexan and slipped it into place. The lexan goes down about 4 inches. When I needed the 2nd piece to thicken the side I simply cut another piece - drained and dried the fuge again. Put the glue on it and slap it in there.