SUBTOTAL function not responding

Hello guys,

I am using the SUBTOTAL function in the attached sheet but its not responding as it used to respond earlier.

Like, if you select any value from the drop down menu on the header, it always returns the same value rather than returning the value based on the visible cells only.

I have tried on other sheets as well but the response is same. Maybe some setting has been changed as it used to work fine earlier. Please help me.

Thanks