Ubuntu 20.04 Daily Build + Urbackup ZFS

Hello,

testing Urbackup on Ubuntu 20.04 Daily Build:
install OK
start urbackup OK
web GUI urbackup OK

but create backup = failed, there is problem with ZFS snapshot, how to debug ?

sudo urbackup_snapshot_helper test
Testing for btrfs…
ERROR: not a btrfs filesystem: /DATA/APP/UrBackup/testA54hj5luZtlorr494
TEST FAILED: Creating test btrfs subvolume failed
Testing for zfs…
TEST FAILED: Creating test zfs volume “pool-xxxx-xxxx/FS-ROOT-APP-URBACKUP/images/testA54hj5luZtlorr494” failed

Backup debug line
HT: Hardlinking failed (unkown error) Source="/DATA/APP/UrBackup/xxxx/190918-0731/xxxx" Destination="/DATA/APP/UrBackup/xxxx/200103-2046/xxxx" – Invalid cross-device link (code: 18)

/DATA/APP/UrBackup/xxxx/200103-2046/ not exist…

thanks

update:
Ubuntu 18.04 - after dist-upgrade contain ZFS 0.8.1 - UrBackup working OK
Ubuntu 18.04 - with PPA jonathonf/zfs contain ZFS 0.8.2 - UrBackup does not work