During the calculation of the retention rate data by using a cohort table, applying the segment with additional conditions changes the column.
This is because because Date Ranges are used as dimensions, which restrict the scope of the segment specifically to that date range. Whereas in Cohort, it takes into account the complete date range.
This can be verified by creating a segment. To create a segment, right click on any cell in the Cohort table. If a segment is created for just the current month from the corresponding cell in Cohort and change the date range in the report, we will find that the numbers match.
This is equivalent to applying purple colored date range as dimension because the date range is restricting to the report date range. However, if we just change the date range to last 5 months, you will see that the numbers exactly match the Cohort table.