I found this elswere but as I am unable to comment, I wanted to post again since there was no solution just that it "resolved itself". I am having this exact problem:
I'm currently experiencing an issue while trying to log into the Meta Business Suite. I enabled "2-factor authentication for everyone," and as a result, I was logged out of my account. Upon trying to access the suite again, I was prompted to select an authentication method. There were three options available, which I'll outline below:
Authentication App: Facebook recommended this method, but when I clicked on it, I received the following error message: "The content you requested cannot be displayed right now. It may be temporarily unavailable, the link you clicked on may have expired, or you may not have permission to view this page." I attempted this for two consecutive days, but the error persisted.
Text Message (SMS): I tried entering my 10-digit phone number (ensuring it was correct), but I continuously received the error message "Please enter a valid phone number." Initially, I assumed that the country code was unnecessary since it was already selected in the first input field. However, when I tried including the country code as well, I encountered the same error. Additionally, there was a warning stating that repeated entry of an "invalid number" may result in account restrictions. I even attempted using my mexican phone number that has a +52 and is completlehy valid while I am travelling in mexico (in case my 10 disit phone number was deemed "used elsewhere" for this purpose)
I couldn't find any helpful information online regarding this problem, and the error message itself is not very informative.
Security Key: Since I do not have a phsical fob this is not only unavailable but not practical. It's crucial for me to access the business suite aat this time.
I'm hopeful that someone in the community can provide assistance or guidance on resolving this issue. Thank you in advance for any help you can offer.
I tried adding different phone numbers and was expecting one to send me an SMS and be added as my 2fa phone source.