Can't resize lvm backup volume storage

I still have no clues to remove or resize my backup logical volume because errors are still here, I tried unmounting backup volume but I still have errors (in use or Error: Invalid value for volume "default_backups-vol" option "size": Invalid value: 160Gib)

I may try to remove lvm logical volume with lvremove then go inside admin sql do this :

But because errors are different I’m afraid that incus will just start with errors and break everything again.

Though it seems my backup volume is empty :

incus storage volume show default custom/backups-vol 
config:
  block.filesystem: ext4
  block.mount_options: discard
description: ""
name: backups-vol
type: custom
used_by: []
location: none
content_type: filesystem
project: default
created_at: 2025-05-29T22:51:00.353476482Z
incus storage volume info default custom/backups-vol 
Name: backups-vol
Type: custom
Content type: filesystem
Usage: 16.00KiB
Created: 2025/05/30 00:51 CEST

If anyone have any idea, thanks a lot