Unable to logon to Azure Portal or access billing information

I have a personal account with an individual Azure subscription. I am locked out of my billing directory due to an 8-digit versus 6-digit Authenticator code mismatch. My Microsoft Authenticator gives me an 8-digit code, but Azure only accepts 6 of the digits, so it's impossible for me to match what Azure is asking for. Notifications from Azure never make it to my Microsoft Authenticator app.

For context, this account is very old, but is still billing me every month, so it's in my interest to have control of the account. It's possible there's a discrepancy between my personal account, under which I signed up originally more than 6 years ago, and the type of account Azure expects (which I understand to be a business account, which mine is decidedly not).