This is said in the problem statement - “A cell in the grid is stable if the number of cells in the grid which are adjacent to this cell is strictly greater than the value written in this cell”. But the accepted solutions have the condition as greater than or equal to.
Here is link to code that had strictly greater condition:
Here is link to some solution that had greater than or equal to condition which were all accepted:
https://www.codechef.com/viewsolution/24324309 (python solution)
https://www.codechef.com/viewsolution/24324345 (c++ solution)
I request the problem setter to kindly look into the matter.