New Field / Column added not getting displayed in Pivot Field List

Hello,

i have two sets of data converted to 2 Tables. i added a new Column / Field in each data set
i made sure to resize the data which houses the new column / Field Created
When i Create a Pivot If I DO NOT select "Add this data to the data model" the new Field is showing up in Pivot table Fields Task Pane
But if select "Add this data to the data model" that field is NOT showing up in Pivot table Fields Task Pane

any help on what i am missing ?

Thanks
R