I changed my mobile handset from android to iPhone and i cant sign in into my customer guest account, as the authenticator code doesnt get reflected in my mobile authenticator app

I have a guest teams account for my customer, besides my main office account. I changed my mobile handset from android to iPhone. I am able to sign in into my main office account, but cant sign in into my customer guest account.

What happens:

1. When i click on the guest account, i get an authenticator code on my screen, but no code is reflected in my authenticator app.
2. I tried using the sign in via 'codes' method, but that too doesnt work

This happening for both, my mobile teams app and desktop teams.

What i noticed was different in my authenticator app than my colleagues is, they have a guest account added in their authenticator app. I dont have it.

When the customer added us to their group, the account was automatically added in the authenticator app. I asked my customer to remove me from the group and add me back into it, but that did not work.

Previously my guest account would work, its now after i changed my mobile handset and updated teams app that its not working.