BE 20.6 VM always incremental

In BE 20.6 there is new feature:

New features/enhancements are included in this release 

• Backup Exec supports forever incremental backups for VMware and Hyper-V virtual machines. It eliminates the need to do frequent full backups of the source virtual machines by creating consolidated full backup sets on the Backup Exec server..

I created in test environment new scheduled job for backup 2 hyper-v VMs every day at 9p.m. to deduplication disk storage. After 2 jobs finished I see, that BE doing classic full backup.

How this works?