Hi Pedro Vieira,
Thank you for reaching out to us on the Microsoft Q&A forum.
Based up on the query you may occasionally experience resource allocation failures because of unprecedented growth in demand for Azure services in specific regions. This problem can occur when you try to create or start VMs in a region while the VMs display the following error code and message: Error: Allocation failed. We do not have sufficient capacity for the requested VM size in this region. Read more about improving the likelihood of allocation success.
Please refer the document for more information: https://learn.microsoft.com/en-us/troubleshoot/azure/virtual-machines/windows/allocation-failure
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