Only thing that comes to mind...Is your IP range 192.168.0.X ? If you blindly copy pasted that macvlan command from that but don't use that subnet the mismatch would be a fatal problem.
other than that I recommend following the official docker.com documentation on macvlan creation.
Edit: Nevermind it looks like you got help in the post you linked Setup on Synology Docker - #27 by coalfield