An Azure backup service that provides built-in management at scale.
Hello @Aviv
Thank you for posting your query on Microsoft Q&A platform.
We have an update that removing the immutability lock requires backend intervention and customer authorization due to security concerns, including potential ransomware risks.
This restriction was supposed to be lifted on 15/04 but was extended by another 2 weeks due to unavoidable circumstances.
So, I wanted to share an update that PG team has been applied fix on this issue and After April 28th you can able to delete backup vault.
Thanks,
Suchitra.