Child filter doesn't update based on the parent filter selection

Hi All,

I have a dataset sample that looks like this: 

Using this dataset I created 2 filters called Sales Model and Dealer and 1 KPI called Machine Count which would update based on Sales model and Dealer selection.

Both filters are single select. 

Dealer is child filter such that is if Petrol sales model is  selected only petrol dealers will show up

Therefore dealer filter, I Edited the interaction (using Edit Interaction in Format Menu) such that dealer filter should not affect values of sales model filter.

Now when I change the sales model filter to any other value.

I expect that the change in the sales model should automatically change the dealer to a default top value in its category. Rather the dealer filter retains the old value that was last selected.

Here is the link to the Report