So I went onto the beta grid to check something. Used -grid aditi as part of my command line. Later, when I went to go on the main grid, I was put on the beta grid instead. No clear way to change it.
I just added -grid agni to my command line to get back to the main grid. But there's a secret grid chooser available. Press Ctrl-Shift-G on the login screen, and select agni.