newsequentialid() default value

My DBMS is SQL Server 2012 and I would like to add newsequentialid() to the default values list for a column. I tried clicking on the "create" button next to the drop down and was able to create the value. It shows up in the list and as the default value in the column listing but it isn't showing up in the SQL preview. If I choose newid() it shows up fine. I did not add newid() it was already there. What am I doing wrong? I'm using PD 16.5

Thanks,

Mark