Looks like the uid/gid map isn’t applied or the filesystem is wrongly shifted.
Can you show (need to run as root):
- lxc config show --expanded NAME
- lxc exec NAME – grep shiftfs /proc/mounts
- ls -lh
/var/snap/lxd/common/mntns/var/snap/lxd/common/lxd/storage-pools/default/containers/NAME/rootfs/
That may give us some clues as to what’s going on here.