Calculate percentage using ALLEXCEPT

Hello,

I have a bar chart as follows using Category on Axis and Segment on Legend -

I have following measure to calculate the SalesPercent in the graph above -

SalesPercent = DIVIDE(SUM(Orders[Sales]),CALCULATE(SUM(Orders[Sales]),ALLEXCEPT(Orders,Orders[Category])))

This is all fine.

However, when I select, lets say, 2 values out of 3 in the Segment slicer -

I want that the percentage should be calculated accordingly and it should sum to 100% for each category.

Instead, here is what I get -

Any inputs??

Regards