Hi, I have the same problem, and I did have an "incident" with my BB core. I did several hot/cold pulls and cleaned the opening of the nozzle with fine acupuncture needles of different diameters, but the problem still persists. The first cleaning blob of the PVA always, literally always, sticks to the nozzle and messes up the print afterwards.
I am using default settings ... any suggestions would be appreciated!
best, Georg