Sorting Matrix headers after unpivoting data

Hello,

I had a data table with information about materials, stocks, demands etc

Wanted to give the user the ability to choose which columns will appear in the matrix

For that I duplicated the table and executed unpivot (see file in the link below)

The problem is, I'm not able to set the order of the columns in the matrix

Any way to fix this?

https://drive.google.com/file/d/1a-8X4TeS7pzsWemyzFHx12M1GaHP0YkE/view?usp=sharing