Difference in results when executing expectations on same data from CSV and Athena datasources


I have a table data with different types of columns (datetime, varchar, integer). When I execute expectation expect_table_columns_to_match_set against same data from CSV I get complete list of 6 unexpected values. But when I execute same expectation against same data from Athena datasource I get only 2 out of 6 unexpected values in the result set.
Can you please help me in knowing why does this happen with AWS Athena datasources?