Stuck in a authenticator loop for my MS business account

Question

I can't verify my Microsoft business account anymore. This is an account I am using from my small company, and I am the admin. Using it exclusively for work purposes, i.e. for various Teams and SharePoint spaces and office applications. It's part of a M365 work package. The signing for this query is through another account, that does not have two-step authentication enables (luckily).

Ever since I got a new phone (iPhone 11 to 15), I've had trouble logging into my account, since the account required further verification in Authenticator. I can now no longer authenticate my own MS account. The associated Authenticator account was no longer producing verification numbers and now I'm stuck in the often reported loop, where to do anything I need Authenticator's verification numbers, but in order to log into the Authenticator account I need its own verification numbers and there's no way out of this recursive hell.

I've read many other posts on this and none of them has offered me a way out. The backup from recovery didn't work and after reinstalling the Authenticator app. My back-up is not in the iCloud. I've logged in to the second MS account on a desktop browser to add a new Authenticator verification, and while I can log into my MS Account, to get to the point where I make security changes, I need Authenticator verification.

I'm lost.

Is there a number I can call? I'm in the Netherlands.

Thank you.

PS My one drive is syncing, but online access is blocked. Very frustrating.