I can select the windows but nothing is happening when I try to move, how can I fix this?
This is likely due to the fact that the application does not have permission to control other windows. To give it access, go to System Settings > Security & Privacy > Privacy > Accessibility and add + enable MultiController.

Does MultiController work with custom in-game controls?
Yes and no. For Mirror, MultiController takes your input and outputs it directly to all of your ToonTown windows. So if you only use Mirror mode, you should be good to go with custom controls.
Unfortunately, the way Multi works is by taking your input and outputting the default controls. If you leave any controls unchanged, they will still work, but any controls that were changed will not.

Nothing on this page has helped me, what else can I do?
Join the Discord server where you can ask any question you have! Discord is free and does not require a download.