DatePicker calendar is hidden behind table header

Question

I'm trying to use react-datepicker in my react-data-grid filter but can't get to show the calendar on top, i tried to set the react popper as suggested here among other configurations but nothing

.react-datepicker-popper {
    z-index: 9999 !important;
}

I'm new to web development, so this might be a dumb problem, anyway here is my code on codesandbox