Be sure to use low expanding foam and i would also place a large heavy object on the floor above to be sure you do not push the flooring up with the foam.
How to fix low spot under floating floor.
It may require nothing more than simply sealing small gaps around your window panes with caulk.
Place the level on different areas of the floor and notice if it lays flat in all spots.
Attach an air inflation needle as an extension onto a can of spray foam.
Floor leveling compound is made for just such a thing.
If a gap appears under the center of the level it indicates a low spot if the level rocks back and.
Any depression that is more than 3 or 4 inches wide is in my opinion too wide.
Mobile home windows also have a tendency to leak and may be allowing water to run down onto your floor where it seeps into the flooring and begins to create soft spots.
For quick repairs of soft spots in your laminate floor use an air inflation needle or a syringe used to blow up sports balls on a can of spray foam.
This should be a simple fix.
Some flooring such as solid wood or engineered wood can bridge small depressions.
Low spots and depressions in subfloor.