I recently had a floating floor of engineered wood installed over plywood. There are some soft spots with one area that is particularly soft. Can that area be repaired without ripping up the whole floor?
Short Answer: probably not.
However, a floating floor should be simple for an experienced installer to dismantle and re-install.
Most likley cause is a slight dip in the plywood floor. Since NO FLOOR is perfectly flat installers need to check level and use the appropriate method for filling low areas. (which can be level compound or cut an extra peice of underlayment and lay in the low spot).
Ask the installer to come back and inspect.
You can eject epoxy in such areas if they are not overly large and save taking the floor up. This method I'd leave to a pro but it does work very well.