is that when the floor expands and contracts, the fillers USUALLY chip, flake, and work their way out.
Fillers are a good band aid though.
Finish problems. If you sand and repair that area, it will most likely stand out clearly. I would consult a professional floor person on this and seek several opinions. Surely there is something to spot treat that area without doing the entire flooring area.
Insurance I am sure will take care of this, but if you do a spot treatment and wait too long, insurance will renig.
If you want it done right, go ahead and let insurance and your ded. fix it right.