Can't mount ZFS dataset

[knacky34]

I'm currently facing issue for mounting datasets of an encrypted pool.

The pool and its datasets had been setup like this:

# Pool creation
zpool create \
    -o ashift=12 \
    -o autotrim=on \
    -O encryption=on -O keylocation=prompt -O keyformat=passphrase \
    -O acltype=posixacl -O xattr=sa -O dnodesize=auto \
    -O compression=lz4 \
    -O normalization=formD \
    -O atime=off \
    -O canmount=off -O mountpoint=/data -R /mnt \
    dpool raidz1 \
    ${DISK1} ${DISK2} ${DISK3}

# Datasets creation
zfs create -o canmount=off  dpool/nextcloud
zfs create                  dpool/nextcloud/data

Auto-mounting is not working but I first would like to figure out the issue using manual mounting.
For mounting the datasets, I used :

zfs load-key -a
zfs mount dpool/nextcloud/data

zfs mount dpool/nextcloud/data command exit successfully but the dataset is still not mounted.
What am I doing wrong ?

Please note that altroot is no longer used (export and re-import pool to remove altroot), see:

$ zpool list
NAME    SIZE  ALLOC   FREE  CKPOINT  EXPANDSZ   FRAG    CAP  DEDUP    HEALTH  ALTROOT
bpool   960M   105M   855M        -         -     3%    10%  1.00x    ONLINE  -
dpool  8.17T   532G  7.65T        -         -     0%     6%  1.00x    ONLINE  -
rpool   106G  20.0G  86.0G        -         -     3%    18%  1.00x    ONLINE  -

[rincebrain]

What are canmount, mountpoint, and mounted set to after that command?

[knacky34]

Here is the result of zfs get mounted,canmount,mountpoint (slightly reorganized :) )

dataset	mountpoint	canmount	mounted
dpool	/data	off	no
dpool/nextcloud	/data/nextcloud	off	no
dpool/nextcloud/data	/data/nextcloud/data	on	no

[rincebrain]

Okay, what does "keystatus" say for them?

[knacky34]

@rincebrain, the keystatus is available for all the 3 datasets.

I've setup root on ZFS on Debian 12, so I have a root pool which get decrypted and mounted fine at boot. But I don't if it's related but dpool is not detected when running zfsunlock from initramfs.

[knacky34]

My issue is related to this #12418
Thank you for your help.