Fixed column width on Matrix with hierarchy on column

Hi,

Before asking the question I want to let you know that I have already tried (one HERE and have seen more) the trick with REPT function to create a width measure and then turn off the "Auto-size column width" on "Column headers" but that did not fix my problem. 

So here is the issue I have:

I have a matrix with some dimensions on Rows, a measure on the Values and Month which is part of the date hierarchy on Columns like this:

The auto-size is set Off and word wrap in On after fixing the width to fit the report:

I have 2 slices for location and year. The column width would only be fixed for the year I have applied width:

But when I change the year in the slicer the column width change as well messing up the report.

How can I keep the width of these column fixed for any selected year in the slicer?

Any helps would be appreciate.