Data integration: Export double data if there is a break in years

Hi,
we have a DSO FCCS-System.
In order to export data we needed to change the 'Data Extract Option' to 'All Data'.
With this option the system is using a MDX-Statement to retrieve the data from FCCS for the export.
This runs fine as long as you are within a year.
We have run the Export with the Start Period: 'DEC-25' and the End Period: 'JAN-26'.
The MDX-Statement retrieves in this case 'DEC-25','DEC-26', 'JAN-25','JAN-26' as 'JAN' and 'DEC' are on the columns and 'FY25' and 'FY26' are on the rows.