ユーザーが2要素認証でログインできません。「各コードは一度しか使用できません」と表示されます

The user was connected with 2-factor auth before. Suddenly he was denied login (after connecting from another device). Trying to solve this i as admin deleted his old account (it was new, no replies yet so we didn’t mind), but the problem repeats when he tried to create a new account:


the user deleted the account from his google authenticator app, and re-scanned the new QR code. that didn’t help.
what “code” is being used again?

Discourse version: 9da9b2e1

「いいね!」 1

Looking for clues for this error message:

Unix Linux Community Forumで新しいアカウントを作成したときにも同様のことが発生しました。2要素認証にバグがあり、サポートされていないと思います。