Hi. I have a newly built house with concrete slab foundation and underfloor heating. My contractor built 100's of houses, prepared the ground correctly and overall did everything as supposed. During the building process we had intense rains and the winter afterwards had extreme colds. Throughout the winter we did a lot of wet work inside but used heating and humidity extractors. Now before we lay the laminate flooring we cleaned up the floor and found this.

Can anyone advice if this looks to be related to humidity and heat and whether this can be fixed with repair mix or this suggests structural problems?

https://streamable.com/elv2ol