In the SquareLine Studio Workspace (not sure what this area is called since it’s not a panel it’s not mentioned in the docs): I have three screens and one of them is off the workspace area to the right. There is no scrollbar to get it back so I can click on it.
Edit: I was able to get to it by zooming way out, and then zooming in with the cursor on the right screen. I would suggest adding a scroll bar to this area.
Zooming doesn’t always allow the screen to come into view. I have to quit and restart to get the screen recentered. I did see in one of the youtube demos what appeared to be a click-drag to move the screens, but I’ve not been able to replicate this.