Hardwood floor: new finish scratching/scuffing
We just installed a new walnut floor: unfinished planks, sanded on site, then applied 4 coats of water-based Olympic satin poly. Very happy with how it looks BUT just noticed a fair number of scuff marks. It's only been finished a couple weeks, haven't even put the furniture back in the room, have just been walking through it, vacuumed it, put baseboards on. The scuffs aren't tactile, nor visible when looking straight down, but they're very obvious when looking at an angle with light shining across the floor.
Is this really such crappy polyurethane? How do we fix?