They're marked as 'Mandatory' columns I believe.
If they're 'Mandatory', then they should be "NOT NULL", right? but they're not all NOT NULL
But is it mandatory?
Sorry to go around in circles. I"ll ask the developer what could cause that combination as I wasn't able to make it happen here. I thought it might be a physical model column property around the Column Not Null Constraint options, but apparently not.