Fails to extract embeded font NWLRBB+LiberationSans

I try to open a document with embeded LiberationSans. The error occurs, and some of the letters are not shown (äöü etcpp).

Acrobat Reader DC Version:   2020.012.20043

Every other PDF viewer I tested is able to extract the font correctly!

(Foxit, Edge, Firefox, evince, atril)

What can I do to fix this? Acrobat Reader seems to be up to date.