Thanks for posting your question in the Microsoft Q&A forum.
To resolve this issue:
- Revert to Original Size: Try changing the VM size back to B2ms and see if the appliance becomes accessible again.
- Create New Appliance: If reverting doesn't work, consider creating a new Veeam Backup for Azure appliance with the desired VM size
- Configuration Backup: Before making changes, always perform a configuration backup of your Veeam appliance to ensure you can restore its settings if needed
- Support Contact: If the issue persists, contact Veeam technical support for further assistance
Please don't forget to close up the thread here by upvoting and accept it as an answer if it is helpful