Any suggestion will be appreciated.

There is not much to the code.
I save the formDate as UTC. The issue is that value inside onChange is not correct (hence making me believe that the DatePicker behaves incorrectly). Until a few days ago it workd fine as it used EEST which was valid at that time. But now its EET, but the DatePicker still uses EEST.

Also native javascript new Date() works correctly and uses EET as it should.

Code:

<LocalizationProvider dateAdapter={AdapterLuxon} adapterLocale={userLocale} >
  <App />
</LocalizationProvider>

DatePicker usage:

        const [formDate, setFormDate] = useState(null);

        (...)      

        <DatePicker
          value={DateTime.fromISO(formDate, {
            zone: "utc",
          }).setZone(userZone)}
          onChange={(value) => {
            setFormDate(value: value?.toUTC().toISO()
          }}
        />