In the image below you can see that after registering a FIDO2-key I cannot login via private mode (I also cannot login on another pc). It still works to disable the key and remove 2fa. Login on Github and Google works fine with this key.
Can you please provide a clear and complete list of steps that allow someone else to reproduce the problem without having to interpret anything, step by step? Also see https://www.mediawiki.org/wiki/How_to_report_a_bug - thanks.
After iterating trough the process multiple times I realized that Webauthn doesn't work crosswiki. It work's only in the same wiki I registered the key.
Do you really wanted me to copy&paste the setup-steps described in https://meta.wikimedia.org/wiki/Special:Manage_Two-factor_authentication???
@Der_Keks: No, I am not "really" asking you to copy and paste content. I asked you to follow https://www.mediawiki.org/wiki/How_to_report_a_bug and provide a clear list of steps to reproduce a problem, for example mentioning that you used https://meta.wikimedia.org/wiki/Special:Manage_Two-factor_authentication (?) though your screenshot implies that you are not on meta.wikimedia.org at all but maybe on de.wikipedia.org. Nobody knows, except for you, so everyone else has to guess.