What you are seeing is a result of the FIXED LoD expression.
FIXED LoDs are calculated prior to regular filters, i.e. it is calculating this before the Local Time filter is applied (Which is why you see the same results before/after)
Here are some options
1. You can do as Sharad suggested and use Include/Exclude LoD
2. You can add the Local Time filter to context (Fixed LoDs are computed AFTER Context Filters)
3. Since all of you Dims are in the viz/worksheet, and you want it to adjust based on filters, you can use Table Calcs instead of LoDs. This method could yield better performance as it would happen post DB/Datasource query from within Tableau on a limited number of dims.
If you run into any problems, feel free to ping me.