Missing SharePoint data fields

[dpaul1031]

I am having a problem. I connected my to my SharePoint online site as my data source.  I picked the lists that I wanted as my tables.  I started creating custom columns and Measures, only to discover one of my fields 'Project Due Date' was missing.  I went to the Edit Query, and found the column in the 'FieldValuesAsText'  and I added the missing field.  However, I cannot use this field for anything.  I does not show up ion the list to use in any customer column, formula, or measure.  

What am I doing wrong?