Folder is not writable by user 'root'

Hey guys, so i’m really new to all of this stuff (and i know i didn’t choose the easy path xD)

But, here my problem :

I got proxmox running LXC with all the stuff i need, sonarr, radarr…
I got TRUENAS on a VM with all my storage.
I did a ZFS pool in Truenas.
I mounted my pool into proxmox using NFS.
I then create a mount point on all my LXC
Everything got to work, except i can’t figure permission’s thing

I want the root folder of sonarr to be mnt/data/sharedfolders/torrent/series, but i got the “Folder is not writable by user ‘root’” error
On trueNAS, i checked the perm to the folder “sharedfolders”
image

Thing is : i can map the folder on “torrent”, but not on “/torrent/series”.

And i can’t map the folder on “/media” either, but torrent & series folder got the same perms…
And i saw some talk about mounted disk but i can’t understand what’s said so i come to got some noob help please !