L'utente non può accedere con l'autenticazione a due fattori. Dice "ogni codice può essere utilizzato una sola volta"

[Alon1 (Alon)]

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

[Alon1 (Alon)]

Looking for clues for this error message:

[red-giant]

È successo ancora a me mentre stavo creando un nuovo account sul forum della Unix Linux Community. Penso che l’autenticazione a due fattori (2-Auth) sia difettosa e non supportata.