Hi Salvador,
Thank you for sharing your query on Microsoft Q&A!
It looks like you're encountering a location-based issue when trying to delete or manage a MariaDB server in Azure. The error message suggests that MariaDB is not supported in the region, and therefore the resource provider cannot process your request using that location and API version.
Please make sure the resource provider is registered in your subscription. Navigate to your subscription and under Resource Providers check for Microsoft.DBforMariaDB Register-AzResourceProvider -ProviderNamespace Microsoft.DBforMariaDB
Use a supported region for creating new MariaDB instances or migrating existing ones. https://learn.microsoft.com/en-us/previous-versions/azure/mariadb/quickstart-create-mariadb-server-database-using-azure-powershell
If the resource appears to be stuck and cannot be managed or deleted normally, consider using Azure Resource Explorer or Azure CLI/PowerShell to manually delete it. https://learn.microsoft.com/en-us/previous-versions/azure/mariadb/quickstart-create-mariadb-server-database-arm-template?tabs=CLI#clean-up-resources
If this answers your query, please let us know. If you still have questions, please let us know what is needed in the comments so the question can be answered.