Empty date columns after web refresh

Hello, 

I'm having an issue with 2 tables that are being filtered through a DIM Date table.

In desktop app and after first upload I get this:

So my DIM date filters the other tables.

After the refresh on the service, this is whats left:

When I try to explore the data on the web service, these columns appear to be empty.

Does anyone have a clue what's happening here?

Kind regards,

Nico