I look into it, the plugin we're using doesn't know how to cope with The Flattening, so the new-fangled name IDs confuse it. I tried to find an update for it, but the developer seems to have disappeared, and as far as I can tell nobody has made a fork (which is really weird).
I've been meaning to make a custom plugin for this for ages now, one that actually does the randomness correctly, as well as a few other cool ideas I've had. In theory it *should* be relatively simple, so I'll put it high on my todo list for when I next have free time
Sorry about that