I can't find the backups of my Microsoft authenticator app

Question

After resetting my phone, I wanted to recover my 2FA credentials using the Microsoft Authenticator app.

I've already done this several times in the past ans the "backup online" mode was always activated, so I was always able to recover my 2FA codes...

However, it turns out that when I to resynchronized my account this time, I get a message telling me that no backup is linked to this account, which is absurd and vert worrying in view of the large app/website I was using via your app.

I checked the account activities ans it seems that a synchronization was attempted and failed from Brasil (I'm in France) on 4th August.

I havent't used my PC for about a month. No connection other than my own to the Microsoft acc. on the website. Microsoft even tells me thete's notjhing to worry about, as thé attempts jave been unsuccessful.....

Well, there must still ne backups of my account , but when I log in the recovery mode, I end up with a brand new account, with no 2FA codes for anything. I've réinstalled the app twice, ans followed the same recovery procedure for the same résult... Btw I'm 100℅ sure I used the right account.

Any help would be vert appreciated. Thanks!