Just watched the news. A father of his child didn't get declaration of paternity, because the new step father of his child was faster with bureaucracy and currently it's impossible for the biological father to legally get this declaration of paternity since the child already "connected emotionally" to the step father. The federal constitutional court said as prejudice, that time shouldn't be considered for a declaration of paternity since the biological father should also be the legal father.

Source: https://www.zdf.de/nachrichten/heute-in-deutschland/heute---in-deutschland-vom-26-september-2023-100.html 5:06-7:11 (in german)