Hi,

This looks like a bug.

We had a same issue with few VMs

After Veeam support was involved they redirected us to Oracle as we use OLVM.

There was in logs

2024-08-17 01:06:12.1818 00022 [4184461] WARN | [RhvBackupManager]: Failed to create incremental backup, fallback to full backup: RhevClient.Exceptions.RhevServerException: Cannot backup VM: Disk is locked. Please try again later.

THe same error was with Vinchin.