Long time ... Phoca Cart was running smoothly for me

I recently updated Joomla to 4.3.3, PHP to 8.2.8 and Phoca Cart to version 4.0.7. Everything worked well but I just noticed that the year date in the Phoca Cart Invoice does not show correctly, PDF and email.
e.g. German invoice and due date:
Rechnungsdatum: 30.11.-0001
Rechnungsfälligkeitsdatum: 30.11.-0001
The order and invoice were generated on 28th of July 2023 so the invoice should read 28.07.2023, die date 29.07.2023 (invoice + 1). Not only the year is strange but the whole date is ... I don't know where Phoca Cart found this information.
Any idea?
Thank you for your help
Alexander