Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Hello @Eduard Viladesau,
Based on your description, it appears that you are unable to access the Azure portal using your personal account because the account is automatically being redirected to an Azure tenant where you were previously added as a guest user.
Since this association was created some time ago, the recommended way to leave the organization would normally be through the organization's portal. However, as you currently do not have the required access or authentication to that tenant, you may need to contact the organization's administrator and request that your guest account be removed from their directory.
Please give this a try and let me know the outcome. Should you have any further questions or concerns, I will be happy to assist.