Date field value is missing if user comes back from confirmation

[Patta]

TYPO3 9.5.15 powermail 7.4.0 composer mode

Language: de TypoScript option forceJavaScriptDatePicker: disabled Locallang datepicker_format_date: d.m.Y form confirmation page: enabled Field type: date Field datepicker_settings: date

If the user comes back to the form from the confirmation view, the date field value is missing and the console error The specified value "16.04.2020" does not conform to the required format, "yyyy-MM-dd". is shown.

If datepicker_format_date is set to Y-m-d the date field value is available after user comes back from confirmation view. Any hints to get this value also in german format? Thanks for your support!