Problems when combining 2 measures

Hey,

I have created to measures to display the closing balance of creditors and debtors per week. When i visualize them seprately they work fine. But when i combine them, the matrix only displays specific weeknumbers out of the date table.

Seperately:

I personally think this is because of the weeknumbers of the starting date of the period: These are the weeknumbers that are shown when i combine the two measures. This is also the column that is linked to my date table.