Filtering on multiple Dates at the same time

Hi,

I have a problem and though of different solutions but none of them worked.

I have this kind of table structure:

Ticket Data

Call Data

As you can see, there is a relation to a customers table.

My goal:
I want my customers to select one year and one month from the filters pane and all the data from the different reports pages get filtered based on the selected month.

What I tried:

- Use a relation between the dates: this wont work because I already have a relation on the Customer

- Use another global dates table: only use measures to display the values and filter in the measure for the selected date. This wont work because I cant use a measure for the date axis in the visuals. Because on some pages I need to display the last 6 Months based on the choosen one.

- Use synced and grouped slicers: I create a year and month slicer in the first Page of the report and sync the selected value to the others slicers. This actually works in the first place, but after publishing it to Power BI Desktop this is not working correctly (also I need to use filter for embedding the reports later, so doing it with filters would be great, if possible),

- Use a calculated column with a calculation to check if the data row should be displayed or not and filter on that value. This wont work because the current filter context is not passed to the calculated column, so it never notifies which date was actually selected.

Of cause in this simple version one could say, come on, let users pick 2 dates. Well I have a lot more such tables from other sources and its all the same problem, there is a customer relation already.

Does somebody have any idea on how to solve this problem?

Thanks in advance, I'm struggling with this a long time now..