Mine did the same exact thing for about 5-6 weeks before it was broken in. I am not really sure what breaking in means though; I was always under the impression that it took several weeks for the shipping oils/manufacturing oils to be cleaned away for the skimmer to start working.
Mine would be fine for several hours and then suddenly act up. It finally stopped after a period of time.
Are you dosing into the skimmer area or the return? Assuming they are separate. I wonder if dosing further away would help eliminate at least one pain in the butt foam up.
I am not sure if this has anything to do with it, but I personally noticed that one of my tanks, with a super oversized skimmer started working like a champ after a few days, whereas the one with an underpowered skimmer took forever. Too many variables (brand/ratio of water to skimmer capacity/more advanced) to know if that has anything to do with it, but just another idea.