Date field format

Hi,

I have a date field in my import PBI report which comes in as a Datetime from the source. In the report I change it to a date value. 

= Table.TransformColumnTypes(edw_vw_fact_Timeline,{{"AppointmentStartTime", type date}})

 Within the Column Tools section, I've selected the field to be of Data Type 'Date' and the Format is dd-mm-yyyy. 

When I put this field in the filter slicer I select that I want to see the StartDateTime field and not the hierarchy. When I select to see the dates in the filter as a list I get the correct format e.a. dd-mm-yyyy.

However when I make the Date Filter a slicer where the user can choose between 2 dates, it reverts back to mm-dd-yyyy. I have no idea why this behavior keeps popping up, and how to fix it.

Any help is greatly appreciated!