"animation : { duration : 0 }" breaks dropdown button behavior

[40rn05lyv]

Steps: Change demo conf to following:

$('#combo-02').scombobox({
    data: [...],
    animation: { duration : 0}
});

Try to use dropdown button to open/close options. Expected result: Select is opened without animation. Actual result: The dropdown button doesn't work anymore .

[Alexander-Shevchenko]

With jQuery 3.4.1 the animation duration = 1 also makes dropdown button not working, increasing to 2 makes it working from the 2nd/3rd time :) { duration : 10 } makes it working OK quite stable.