Unidad apfs externa (encriptada) dañada en High Sierra

Tengo problemas para acceder a los datos de mi disco USB externo llamado G-DRIVE USB - simplemente no se monta. Me sale el aviso de desbloqueo, y lo hago, pero no hace nada.

DiskUtility no se abre cuando esta unidad está conectada - muestra "cargando discos" y no hace nada.

Hasta ahora he intentado acceder a los datos manualmente utilizando los siguientes comandos de terminal:

  @MacBook-Pro:~$ diskutil list
    /dev/disk0 (internal, physical):
       #:                       TYPE NAME                    SIZE       IDENTIFIER
       0:      GUID_partition_scheme                        *251.0 GB   disk0
       1:                        EFI EFI                     209.7 MB   disk0s1
       2:                 Apple_APFS Container disk1         250.8 GB   disk0s2

    /dev/disk1 (synthesized):
       #:                       TYPE NAME                    SIZE       IDENTIFIER
       0:      APFS Container Scheme -                      +250.8 GB   disk1
                                     Physical Store disk0s2
       1:                APFS Volume Macintosh HD            189.8 GB   disk1s1
       2:                APFS Volume Preboot                 20.0 MB    disk1s2
       3:                APFS Volume Recovery                519.9 MB   disk1s3
       4:                APFS Volume VM                      1.1 GB     disk1s4

    /dev/disk2 (external, physical):
       #:                       TYPE NAME                    SIZE       IDENTIFIER
       0:      GUID_partition_scheme                        *4.0 TB     disk2
       1:                        EFI EFI                     209.7 MB   disk2s1
       2:                 Apple_APFS Container disk3         4.0 TB     disk2s2

    /dev/disk3 (synthesized):
       #:                       TYPE NAME                    SIZE       IDENTIFIER
       0:      APFS Container Scheme -                      +4.0 TB     disk3
                                     Physical Store disk2s2
       1:                APFS Volume G-DRIVE USB             2.9 TB     disk3s1

Si intento repararlo:

@MacBook-Pro:~$ diskutil repairVolume disk3s1
Started file system repair on disk3s1 G-DRIVE USB
Repairing file system
Volume is already unmounted
Performing fsck_apfs -y -x /dev/rdisk3s1
Checking volume
Checking the container superblock
Checking the EFI jumpstart record
Checking the space manager
Checking the object map
Checking the APFS volume superblock
Checking the object map
Checking the fsroot tree
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
warning: invalid dstream.default_crypto_id (0x0) for encrypted volume, given apfs_fs_flags (0x8)
Checking the snapshot metadata tree
Checking the extent ref tree
Checking the snapshots
Verifying allocated space
The volume /dev/rdisk3s1 appears to be OK
File system check exit code is 0
Restoring the original state found as unmounted
Finished file system repair on disk3s1 G-DRIVE USB

Y no se monta:

@MacBook-Pro:~$ diskutil mountdisk disk3s1
One or more volume(s) failed to mount

¿Qué más puedo hacer? ¿Alguna idea? Gracias.