It seems when you play in duo mode in the new Theatrhythm Final Bar Line, the support for the 2nd player/controller seems broken, and there is no prompt asking the user to setup additional controller that is launched (when it’s usually the case for other multiplayer games).
Tried on yuzu build1330 (2023-02-05)
Thank you for your time and have a nice day.
Edit: After further testing, is looks like it’s working correctly.
I’m not sure what I did wrong the first time trying, but it seems my issue is now gone after restarting yuzu.
Sorry for opening this case, it can be closed, thank you!