I just polyurethane 700 sq ft. of hardwood flooring
Oil based? 48 hours should have been plenty of time. You sure it's not water-based?

Either way, give it another day or so. Rub out the sins with some 220 by hand, making sure to feather it out. Re-poly just the affected board (s).

If that doesn't fly, I know you don't want to hear it, but recoat the whole floor.