When setting up a new access to 2FA using the same email address, this error can occur:
Please note: This is a bug on the Microsoft side, as explained in this source.
As a workaround, instead of using the QR code for installation, please follow these steps:
Manually copy the code that is displayed on your screen and click on NEXT:
You will now see the option: OR, ENTER THE KEY MANUALLY. Click on it to proceed.
Insert the code you copied into the Microsoft Authenticator app manually. This will initiate the installation process for MFA (Multi-Factor Authentication).
This should enable the installation and setup of MFA without the error associated with using the QR code.