Hello anonymous user - Thank you for your post and I apologize for the delayed response!
Microsoft Azure has two platforms - Legacy and Microsoft Customer Agreement (MCA).
If you are using an old subscription it falls under Legacy and doesn't show up as Azure plans. However, if its a new subscription it shows as Azure plan.
The behavior you observed could be because of the region you are in. For your reference - https://learn.microsoft.com/en-us/azure/cost-management-billing/microsoft-customer-agreement/microsoft-customer-agreement-faq
If you've more questions and needs clarity, I suggest you reach out to us by raising a support request to Azure subscription management team using this link - https://learn.microsoft.com/en-us/azure/azure-portal/supportability/how-to-create-azure-support-request
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