Azure Data Factory Data Flows Filter

I am using Data Flows Filter to retrieve only rows by comparing values in 2 columns. For example, I want to filter only rows where value in column1 is not equal column2. 

I am able to get the result as expected when the no. of rows in the source file is less but it does not work when the source file has many records (like 20K records). Please suggest why this behaves like this or is there a better way to achieve this. Example below: