Interesting effects with calendar-based time intelligence

Hi SalvaC , 

when you expanding 2023, it changes the PY results of 2024. It is a bug in the new calendar-based DATEADD() implementation for custom weekly calendars in that specific semantic model. Instead of using calendar-based time intelligence, better to use Classic Time Intelligence. Please try below measure.

Online Sales PY Weekly-Dates  =
CALCULATE(
    [Sum Online Sales],
    DATEADD('Week-Date Calendar'[Date], -1, YEAR)
)

The new calendar-based TI behaves differently because it works from the tagged calendar and its current filter context.

If you are still experiencing the issue, as you mentioned, the new datamodel (ContosoRetail_Sale) is working fine, but the problem persists with the old datamodel (ContosoRetail_Small). Please update the Date hierarchy fields in the old datamodel to match those in the new datamodel. Refer to the screenshots above for guidance.