@farokh one backup job should leave one snapshot. this is the way. to differentiate from previous backup the data to be put in the delta, it has to refer to this snapshot. delete it and you get a full backup ongoing. if you have two snaps on your VM, either you have a manual one, or you have multiple backup jobs backuping this VM (check the backup tab of the VM ?)

@Pilow Double checked. There's no filter in place and no new VM.

@Biz365 Warm migrations from ESXi are ESXi license dependent on what you have/had with ESXi. Otherwise you can replicate the VM using the migration tool and then manually shutdown the VM on ESXi and then power it on XCP-ng.