Jul 12 11:36:40 Tower emhttpd: error: share_luks_status, 6151: Operation not supported (95): getxattr: /mnt/user/lxc
This appears to be the problem, you should not create any mountpoint in /mnt/user, those should be reserved for Unraid array/pools only.
Also I believe ich777 recommendeds not using a FUSER path for LXC for performance reasons, use /mnt/cache/lxc or /mnt/disk#/lxc