my solution in python3 .. might not be the fastest but passes all tests..

def gridChallenge(grid): rows = len(grid) cols = len(grid[0])

for i in range(rows):
    grid[i] = sorted(grid[i])

for j in range(cols):
    for i in range(rows-1):
        if grid[i][j] > grid[i+1][j]:
            return 'NO'
return 'YES'