Ive had the same....Im now going back over all the locations and have found the answer ! Look for anything that is moveable, theres usually something you can do with it that will lead you to another portal where you can press a button and collect stars/points. I`ve found about 7 or 8 of these in Nostrodamo alone. Cases you can push, boxes that turn into electric bits that you can then push to fix broken leads, watering can that needs to be pushed up the earth alongside it...etc etc.
