PASTWEEK() & PASTYEAR() formulas in widget

Hello, I am having an issue creating a report looking at the week as defined by my dashboard filter versus the previous week as well as the equivalent week in the year before.

Basically, I get my 'original' week very easily. We use Last week in the dashboad filter on the TransactionDate for it to report on the latest (most current) completed week. I saved that as a 'TW Units' which basically comes just down to 'sum([Quantity])', likely the easiest formular available in Sisense.

Using the formula PASTWEEK(TW Units) I am getting the results for the previous week and they match what I pull via SQL from the raw data as well.

In my mind I should just need to use PASTYEAR(TW Units) and should be getting the results from the preceding year for the week I am actually looking at. Instead I am getting returned the same results of the week I am looking at for the current year.

Are those 2 formulas different somehow? There is noting in my elasticube that treats the dates any different.