Inconsistent Sum/Total in Matrix

Hi Msampedro ,

Thanks for getting back. Yes, the main issue was due to how the many-to-many relationship between the Net Sales and Mapping tables allows a single material to be associated with multiple layers. This causes the matrix visual to re-evaluate the total across all matching combinations, including ones not directly visible in the row-level breakdown - which results in a higher total.

To fix this, here is a measure that explicitly sums Net Sales per unique Material–Layer combination from the Mapping table.

Net Sales (Fixed Total) = 
SUMX(
    SUMMARIZE(
        'Mapping',
        'Mapping'[Material],
        'Mapping'[Layer]
    ),
    CALCULATE(SUM('Net sales'[Net Sales]))
)

This forces the matrix to total exactly what is shown in the rows, avoiding the  context from the many-to-many relationship. With this change, the matrix total now becomes 29.73M.

Hope this helps. Please reach out for further assistance.

Please find the attached .pbix for reference.

Thank you.