Hello @Abishek D ,
I Understand that you are using Microsoft Authenticator apps for the past three years. You had a problem with your phone, and accidentally deleted the authenticator app.
But when you installed the app and signed in again you did not get the list of codes and recently switched to a new smartphone and have completed recovery successfully on the new phone, but only the sync account is showing up in the 'Authenticator' tab on the new device. Backup is enabled on the previous device and says the backup was last and you are using a OnePlus 11R Android phone. Now you are using new OnePlus Nord 4.
If the codes aren't syncing, you may need to manually reset the two-factor authentication (2FA) for each service you use. This process may require verifying your identity through email, phone, or other methods. It will remove all existing authentication methods, and when you re-register, you'll be asked to set up new ones.
I understand that this situation is really frustrating, especially since it's affecting your work. Let me know if you need more specific help with troubleshooting!
If you are still facing the issue I want, you to contact the support team.
You can look into the article below to get support numbers depending on your country.
or creating a ticket through a different account: https://learn.microsoft.com/en-us/microsoft-365/admin/get-help-support?view=o365-worldwide#phone-support
Once you create a ticket with the support team you will have to work with our data protection team. You will have to first prove your identity against your tenant for security purposes. Post that this team will help you with restoring your authenticator codes depending on your scenario.
If you need further assistance, please feel free to ask.