Nether portal not working, HELP!

I recently added a new spawn, I imported it with Multiverse, but now when I use nether portal it doesn't teleport me at all, the world doesn't have a nether world and its name is RealSpawn, when I type /mv create RealSpawn_nether NETHER then it still doesnt teleport me, please help!

Server IP: burgercrafters.mcpro.co