Fixing voids and soft spots in newly installed hardwood floor
I installed a new hardwood floor at my place recently. It's a floating engineered wood floor over concrete slab. I realize the concrete subfloor should be pretty flat in order to prevent voids, soft spots, or squeaking. But being an amateur, I couldn't really tell that the floor was uneven before I started -- it seemed pretty flat to me at the time.
I guess I must have missed a few spots, but right now there are a few spots that feel "soft". It's not too bad, but I'd definitely prefer if it felt more solid.
Is there a simple way to fix this, without taking out the floor (or pieces of the wood)? I found that for glue-down engineered floors, there is a product called DriTac -- a kit that lets you drill a hole into the wood and fill it with some adhesive using a syringe. Would something like this work for my floating floor?