IS NOT NULL not functioning as expected

Hello,

When trying to apply 'IS NOT NULL' operator as filter(where to_date(column) Is Not Null) on the DB column  it is not working as expected and pulling the null values into the result.

We are using HANA Revision 33.Below is the SQL generated from BO tool we are using BO 4.0.

Let me know if you have ever faced this issue.

thanks!