Filter actions to reset dashboard showing nulls

Good Morning,

I have created a dummy dashboard see attached. The dashboard includes several filter actions, the first action is based on Type data "Salary or O&M", the second is a reset filter to clear any selections the user has chosen and the third is YTD filter to show only months that have occurred including actuals. My issue is with the YTD filter see calculation "IF [Month] <6 THEN "YTD" END" this formula works to filter down however when I use the reset filter it shows the null values for the months that >6.

Does anyone know a way I can change this calculation so null's will not return after resetting?

Thanks,

Jeff