From here (just in case): To rename an asylum journal, login as the maintainer account and select the asylum from the "Work as user" menu and click "Switch".
Also, did you use the same e-mail address for both the maintainer journal and the community you want to rename? Sometimes it's a matter of the e-mail addresses matching up, not the passwords. And I know it can take a bit of time to switch over once it goes through. I renamed an account, and it took awhile for it to mark it as no longer deleted and purged.
If that doesn't help/work, I'm not sure. Maybe use a new password for both and try it that way? Or put in a support ticket if this is something you can wait on. Otherwise, maybe use the rename token on a journal, then turn the journal into a community (which, just in case, how to do that can be found here).