Incremental Image Backup - Same size as Full Backup?

Hi all,

I have started up with UrBackup a week ago and set it up to create daily incremental backups for particular folders and weekly incremental image backups. Unfortunately today I realized that those incremental backups have the same size as the full ones:

I am using UrBackup in a docker environment on a Synology NAS. What is the reason the incremental backups are so big? I am pretty sure this is not how it should be, but my question is what am I doing wrong?

Thanks!

Ok, I have now triggered an incremental image backup again and watched the data being transfered, and this does not match the size being claimed by the UrBackup web frontend. Synology NAS uses btrfs as file system. Is it possible that what I see here is actually the size of all incremental backups in sum and not the last one being made? So basically all the incremental backups are referencing the same physical blocks?

Thanks!