Drop down with filter changes postion from above to below when shortened

I have an issue where the initial popup is opened above the drop down list and when you filter and the list becomes small enough it drops below the anchor. 

 Problem is when the drop down is on the bottom of a scrollable page the drop down is obscured and the user can't select the value because the drop down is off screen and when scrolling it closes automatically.

Is there anyway to make the position of the popup sticky? 

thanks

Justin.