Aqua C Remora Protein Skimmer

[Ruth]

So I just bought an aqua C remora pro and set it up yesterday on my 24g. At first it seemed to skim and get a little in the collection cup but then it just stopped producing anything for the cup. It still bubbles away it is just that the bubbles don't seem to flow over the neck into the cup. I have tried adjusting the height of the cup but nothing. Do these things take a few days to get broken in or do you just have to keep fiddling with the cup height?