Workspaces are not bound to displays in hyprland. This is one major reason I'm using hyprland over niri, where it's not really possible to work around that issue.
Every monitor has its own set of workspaces. Workspace 4 on display A is not the same as Workspace 4 on display B is not the same as Workspace 4 on display C.
Functionally you can focus any workspace on any monitor, and ids do not change when doing that. You can set things up both ways, but it's actually easier to just have a key focus workspace x on the current monitor than to lock workspaces to specific monitor.
