Problem occur when window resizing

I have adaptive layout and the width of my select element changing on different sizes of window. So my select2 element do not respond to the window resizing.

On the first pic its ok. But when I go to the smaller layout my select2 don’t change its size. I need to refresh page and than it become ok.
Does anyone know how to fix it? How to make select2 to be responding?

How are you setting the width of your Select2? If you specify the width configuration property with a percentage value, it should adjust its size based on the size of its container.