react-select inside react-dates doesn't update select value - react-select

Question

I'm using react-dates for a simple birthday picker. I'm using the renderMonthElement prop to render 2 selects on top of the datepicker for months and years:
Whenever I select a month, the calendar updates correctly however the value shown in the react-select component doesn't update.
My Select looks like this:
<Select
placeholder="Monat"
styles={{ indicatorSeparator: () => {}, ...customStyles }}
options={months}
filterOption={createFilter(filterConfig)}
name="months"
value={bdaymonth}
className="monthSelect"
onChange={optionSelected => {
onMonthSelect(month, optionSelected.label)
setBdayMonth(optionSelected.label)
}}
/>
as soon as I take it out of the renderMonthElement, it works perfectly fine by either using bdaymonth from state or just directly with months.label
I thought it might have something to do with the SingleDatePicker being rendered in a Portal but even if I render it inline, the issue persists.
Here is the complete code of my renderMonthElement (pretty much stolen from https://stackoverflow.com/a/57666932/6118046) :
const renderMonthElement = ({ month, onMonthSelect, onYearSelect }) => {
let i
let years = []
for (i = moment().year() - 16; i >= moment().year() - 100; i--) {
years.push(
<option value={i} key={`year-${i}`}>
{i}
</option>
)
}
const months = moment.months().map((label, value) => {
return { value: value, label: label }
})
return (
<BdaySelect>
<div>
<Select
placeholder="Monat"
styles={{ indicatorSeparator: () => {}, ...customStyles }}
options={months}
filterOption={createFilter(filterConfig)}
name="months"
value={bdaymonth}
className="landSelect"
onChange={optionSelected => {
onMonthSelect(month, optionSelected.label)
setBdayMonth(optionSelected.label)
}}
/>
</div>
<div>
<select
value={month.year()}
onChange={e => onYearSelect(month, e.target.value)}
>
{years}
</select>
</div>
</BdaySelect>
)
}

Answer 1

Got it working by changing the value of the Select to
value={months.filter(function(month) {
return month.label === bdaymonth;
})}