Social media Two-factor authentication accounts

Hi

I have hard reset my 2 android phones so they are like they have just been bought.

I have reinstalled the authentication app and scanned the QR code with my phone on the website it added the e mail accounts i have, 3 in total a Hotmail email account and two talk talk email accounts added.

I back up my accounts but it only allowed me to back up one of them, the Hotmail email address account (which I have had for over 15 years)

It then added an extra Hotmail email address account to the app and this shows an 8-digit one time pass code.

The Hotmail email was the original account I’ve had for 15 years and I presume it must be the main account as I tried to back up one of the talk talk accounts and it shows the Hotmail account instead that's been back up.

I was hoping this would restore all my social media Two-factor authentication accounts but it hasn't.

How do I get my old social media accounts back?

Should I delete all accounts and the app and start again on both phones?

Thanks