@SQLBalls from @TalesfromtheField walks us through how to do a Cross Subscription restore with TDE enabled.  This is a very common scenario.  In Azure we have DevTest subscriptions where most customers will have their Development, Staging, or UAT environments to save on licensing costs for Azure SQL Managed instance.  Their Production will be in a separate subscription.  If you need to do a "Prod refresh", where you restore your Production databases to your Development environment there are steps you must follow.  We lay out the scenario, the prerequisites, and then demonstrate how to accomplish this.

Chapters
00:00 Prerequisites
01:21 Cross Subscription Database Restore Scenario
02:24 Azure Key Vault Backup Up of Prod Key
02:52 Azure Key Vault Restore Prod Key to Dev Failure
03:18 Azure Key Vault Create Key Vault to be moved
04:02 Azure Key Vault Restore Prod Key to Key Vault to be moved
04:21 Azure Key Vault Migrate Key Vault to be moved to Dev Subscription
05:07 Azure Key Vault Back up Key Vault to be moved key
05:22 Azure Key Vault Restore back up key to Dev Key Vault
05:47 SQL MI Associate new key with Dev SQL MI Instance
06:34 Azure Blob Storage Get SAS Token
07:11 SQL MI Prod Create Database Scoped Credenital & make COPY ONLY Backup
07:38 SQL MI Dev Create Database Scoped Credential & restore COPY ONLY Backup
08:17 SQL MI Validate Restore

Recommended Content:
About Azure Key Vault: https://learn.microsoft.com/enus/azu...
Moving an Azure Key vault to another subscription: https://learn.microsoft.com/enus/azu...
Grant limited access to Azure Storage resources using shared access signatures (SAS): https://learn.microsoft.com/enus/azu...
SQL Managed Instance with customermanaged keys: https://learn.microsoft.com/enus/azu...
SQL Server back up to URL for Microsoft Azure Blob Storage best practices and troubleshooting:
https://learn.microsoft.com/enus/sql...