Same here. Yes, we're using the 9-digit network ID. I was able to do it from my computer, but my son's computer just gets password rejected. Have uninstalled/reinstalled using the deployment link. Have removed password and set it to automatic acceptance -- his client just says password required, then rejects the password. We have tried multiple different passwords.
If you could tell us about the affected operating systems and software versions it may help us understand the problem better.
If the client is on your account, they can be connected to the network on web with a few clicks, no join requiredments needed.
Also it'ss possible to create a deploy link on your end, where the freshly installed client will be joined to a given network automatically.