I had a contractor install Brazilian cherry floors over concrete pad last July and now there is 3 sections that are buckling, he has left the area and no longer can he honor his workmanship. I live in the Caribbean and the humidity is high always between 70 and 90 %. We like to keep the windows open 5 months of the year and the rest on a/c. We used bostik MVP and bst adhesive but can only find mapei 990 now to reapply the boards. Another flooring contractor wants 1800 to fix the 120 sq ft of floor but I think I need to do this myself as it's likely the floor will continue to have issues. Does anyone have suggestions to minimize the buckling, reapplying new boards and etc.... I am a newbie to the forum and would appreciate any help..

Is the relative humidity between 70 and 90 percent all year? What is the RH when you run the AC?

AC in the Caribbean, really? I guess.

The floor must be cut long somewhere and is locked in causing the floor to buckle when it expands. Check perimeter and under door casings.

Use a paper clip, leave one end L shaped so when you slide it under the casing (if you can) you then rotate it and try an slide it back and forth to detect any gaps or lack of.