All columns are correct, and all rows are correct. But blocks (3x3 small squares) are not correct.

then what row and column incorrect ?

oh thx :D i forgot it

each column, each row, and each of the nine 3x3 sub-grids (also known as blocks) contain all of the digits from 1 to 9

Does this clarify things?

check the 3x3 subsquares

Test Failed
Test:
{1, 2, 3, 4, 5, 6, 7, 8, 9}
{2, 3, 1, 5, 6, 4, 8, 9, 7}
{3, 1, 2, 6, 4, 5, 9, 7, 8}
{4, 5, 6, 7, 8, 9, 1, 2, 3}
{5, 6, 4, 8, 9, 7, 2, 3, 1}
{6, 4, 5, 9, 7, 8, 3, 1, 2}
{7, 8, 9, 1, 2, 3, 4, 5, 6}
{8, 9, 7, 2, 3, 1, 5, 6, 4}
{9, 7, 8, 3, 1, 2, 6, 4, 5}
Expected: False
But was: True

Why this test is false ??