Unable to switch directory after configuring MFA – no authentication code received

I have one account that belongs to multiple Azure directories, and I am the Owner of the subscriptions.

Previously, before MFA was configured, I was able to switch directories without any issue. However, after configuring MFA, I am no longer able to switch directories.

When I attempt to switch directory, Azure prompts me to sign in again and enter an authentication code, but I do not receive any authentication code (no notification in Microsoft Authenticator, no SMS, and no other MFA prompt).

Because of this, I am unable to switch directories.

This is a concern, as I need to switch to the other directory in order to add another admin account. I am worried that if this issue happens again in the future, I may completely lose the ability to manage that directory.

I have previously logged a support case with Microsoft. They advised me to reset my MFA methods, but this did not resolve the issue.

Please assist in identifying the root cause and provide a permanent solution.