Measure does not work with slicer/filter

[mmkw123]

Hi guys, 

I am new to PowerBi and have a question regarding the interaction of filters with measures. I have a slicer on the page called "TimestampHistory". It interacts with all visuals on the page but with two very simple custom measures: 

1. 

Active Measures =

DIVIDE(

    SUM('Database (hist)_Status'[Measure Operativ]);

    COUNTA('Database (hist)_Status'[MN-ID])

)

2. 

Weighted Degree of Achievement=

DIVIDE(

    SUM('DatabaseAkt (hist)'[Completed Days]);

    SUM('DatabaseAkt (hist)'[Duration in Days])

)

Now my question is whether I have to include the usage of said slicer into the measure formulas or if there is another workaround?

Thanks a lot in advance! 

[HotChilli]

"I have a slicer on the page called "TimestampHistory"." - What are we selecting in this slicer? 

-

The two measures : are they on card visuals or part of tables/matrix? Please specify.

What is the expected result from selecting something in the slicer?

--

Can you provide a link to the pbix or at least a data model picture for starters?