Knockout View Rebinding

I have just started working on KnockoutJS and MVC 5 EF 6.
Query : -On One view i Add item to Cart with ID,name and Price. Then i Looked what i got in cart on another View (cart View). It's Fine. [I'm using View Model for Bindings of Knockout JS].
I again switch to add more item into Cart but this time when i looked in Cart view it don't get updated ....means newly added items are not there.
I use shift F5 or simple F5 on cart view and it shows the newly added data. I'm binding(KO Bindings) View on page load.

Why i need to use shift F5 although it should updated when i switch to Cart View .Am i doing something wrong..?
Thanks
ROHIT