"the specified server does not exist"

I have a waterfall server set up with a few playable servers, all hosted on the same physical machine. Ports are forwarded for all of them and they are all running on different ports. I can connect to them individually by using ip:port when launching the game, and if I just join the default server (waterfall port) it puts me into the hub world correctly. However once in a wold via joining the waterfall server, I can not switch to a different server. The /server command shows the servers I am running, but gives the error “the specified server does not exist” when I click on them. I am at a loss.