Duration on WBS band

Hi All
I think all of us notice the underneath matter:
- In my schedule there are 2 calendars 5D/W & 6D/W
- Defualt calender is 5D/W
- Activities group and sort by WBS levels
- Then the duration column on WBS bands match defualt calender and ignored the related activities’calander (6D/W) under WBS bands.

Please advise how can work around to avoid that

Thanks

Hady