Adobe Sign removes digital signatures

Hi experts! I am struggling to properly sign a document with Adobe Sign. Maybe you have some experience with a similar issue and can share your solution.

The document I am trying to sign was provided by a German authority and has a digital signature on it. Apparently, it is a signtature using „PADES embedded' and it is a qualified electronic signature.

If I sign this ducment with my own signature in Adobe Sign -> what happens is that it REMOVES the signature that was originally on the document. So afterwards, instead of 2 signatures, it contains only one (my own). The authorities dont accept the document anymore,  cause they need their signture to be on the pdf as well.

Has anyone experienced a similar issue? Is there possibly a setting within Adobe Sign where I can select to not remove existing signatures?