I have various Safari windows, TextEdit docs, and Stickies notes that relate to different things (e.g. work, home). I want to split these across two Mission Control desktops depending on what they are for. On Mission Control, I can't seem to drag these separate windows or even whole apps (collection of windows via the icon) into a desktop – the drag action works, the plus square appears, but the item then just springs back. Same for hovering it at edge of screen.
Update: these apps had "Assign to All" set – changing to "Assign to None" via Dock did the trick 🙂
Best Answer
If the item you're trying to move springs back then it's most likely already on the space / desktop you're trying to move it to.
You can also try moving something to another desktop in ways other than Mission Control:
Apps are automatically assigned to the Desktop / Space where they are launched for the very first time. You change this by Control clicking the apps icon in the dock, and assign to None.