Based upon the name and date, I believe this is related to the kubernetes → docker migration that occurred with TrueNAS release 24.10. When I expand the option for one of the snapshots…
I haven’t done the k8s->docker migration therefore I do not know if those are safe delete.
But I can give you a command to delete them. Use at your own risk.
The following will generate a list of zfs destroy commands that deletes snapshots which contain the fragment @ix-applications-backup-system-update. This way you get a preview of the commands first. You don’t need to be root to generate the preview.
/sbin/zfs list -t snapshot -o name | grep '@ix-applications-backup-system-update' | while read line; do echo zfs destroy -v "$line"; done
In order to delete “for real”, you can replace the word echo with sudo.