@Alejandro Galeano Torres Can you pls share the steps you are following to change VM Subscription?
This article describes special cases that require extra steps when moving a virtual machine to a new resource group or Azure subscription. If your virtual machine uses disk encryption, a Marketplace plan, or Azure Backup, you must use one of the workarounds described in this article.
Virtual machines created from Marketplace resources with plans attached can't be moved across subscriptions. To work around this limitation, you can deprovision the virtual machine in the current subscription and deploy it again in the new subscription.
Resources that have dependencies on other resources in the current subscription can also cause validation failures. Ensure all dependent resources are also moved or reconfigured.
Please check the suggested article and let me know the results.