Bitlocker Key -- I keep receiving a wrong single use code when trying to get the key

If the single-use code keeps failing, the most likely causes in this scenario are repeated requests, delayed delivery, or a temporary verification block.

Recommended steps:

1. Stop requesting new codes repeatedly. Excessive or repetitive requests can trigger a temporary block, and delayed emails can make an older code arrive after a newer request.
2. Wait before trying again. Microsoft guidance says waiting a day can remove a block. If it still fails after 24 hours, wait longer if possible, up to 1 week.
3. Check Junk/Spam in the mailbox receiving the code. Valid verification emails come from @accountprotection.microsoft.com. Mark that sender as trusted.
4. Make sure the code is being checked in the correct mailbox. Verification codes can only be sent to the primary alias or another email already added as a sign-in verification method.
5. Use a privacy/InPrivate window if one Microsoft account is being used to verify another Microsoft account. Sign in to the account requesting the code in one private window, then open a second private window and sign in to the alternate email account to retrieve the code. This avoids automatic sign-out between accounts.
6. Try another network. Switch between Wi‑Fi and mobile data, or try a different Wi‑Fi network.
7. Try another verification method already on the account. If another method is listed during sign-in, use that instead.
8. If access to the current email is no longer reliable, select I don't have any of these during sign-in and follow the prompts to replace the security info.

About receiving the code by phone:

• A phone option is only available if a mobile number is already added as a verification method on that Microsoft account.
• VOIP numbers cannot be used for sign-in or verification codes.
• If no phone method is already on the account, it cannot be switched to phone at that step unless another working sign-in method is available to update security info.

Important limitation:

• Support agents cannot send verification codes or change account details.
• If sign-in still fails, use the sign-in helper or Contact Support from Microsoft Support.
• If the BitLocker recovery key ultimately cannot be retrieved, the accepted guidance in similar BitLocker cases is that the only remaining option is a clean Windows reinstall, which erases data on the drive.

References:

• Troubleshoot Microsoft verification code issues | Microsoft Support
• cannot get past the bitlocker screen on new laptop - Microsoft Q&A