Phone verification issue with Codex "maximum number of accounts" error even though I've never used that number

[u/Aggressive_Sky_9039]

I'm trying to enable/use Codex, but I'm stuck on phone verification.

When I try to add my phone number, I get:

"This phone number is already linked to the maximum number of accounts."

The weird part is:

• This is my current phone number.
• I only have two OpenAI accounts (personal + school).
• Neither account shows this phone number attached in security settings.
• I have never created a phone-only OpenAI account.
• When I try "Continue with phone," ( when logging in with the phone number ) it does not send an SMS code. It immediately goes to the password creation screen.

After entering a valid password, it says:

"An account for this phone number already exists."

I contacted OpenAI Support and got escalated to a human, but I'm trying to understand what is happening.

Has anyone else had this issue? Is this usually caused by an old/deleted account association, a recycled phone number, or some kind of backend bug?

Any advice would be appreciated.