https://bugs.winehq.org/show_bug.cgi?id=46447
--- Comment #4 from Gero gero45@mr-gero.de --- (In reply to Rosanne DiMesio from comment #3)
Sounds like you are looking in http://dl.winehq.org/wine-builds/debian/pool/main/, which is where the old packages were stored.
Packages are now stored in http://dl.winehq.org/wine-builds/debian/dists/buster/main/binary-i386/ and http://dl.winehq.org/wine-builds/debian/dists/buster/main/binary-amd64/.
You probably haven't added the new repository key, either. You need to, then run sudo apt update and answer yes when it prompts you to accept the repository changes. https://wiki.winehq.org/Debian
Thanks for the fast answers and for your help.
You are right (at least with the first part), I looked in the wrong folder. I'm sorry for that.
But I know now what the problem is, "apt upgrade" is keeping the new wine-staging packages back.
I will report back, when I'm able to install the new version.
Regarding the new repository key: I had already added the new key, but only because I somehow looked at the Wiki Page and noticed the head message about the key change.
But I didn't see any message in the package-"NEWS".