Problem with multiple multiple select2 in tabs within asp.net web forms

Within an asp.net web forms form I have implemented the select2 multiple plugin, at the moment of scrolling within the page the element loses the style and is known in the way it is shown in the image, some way of solving the problem?

This is my code:

function prueba() { 
    $("#prueba").select2({ 
        multiple: true,
        placeholder: "seleccione", 
        //dropdownParent: $("#pruebaa") 
    });
    prueba2();
}

function prueba2() {
    $("#prueba2").select2({ 
        multiple: true,
        placeholder: "seleccione", 
        //dropdownParent: $("#pruebaa2")
    });
}