Just tested myself in Maya 2024, it appears that it's giving the UV Editor back focus when you let go of space...
It seems to be an issue with the hotbox, shift > Clicking on an option like Layout in the UV Toolkit lets the options panel take focus. As does accessing options using the marking menus.
Don't have an actual solution if you want to use the hotbox access, but workarounds until a fix is presented could be one of many.
1. Work with the UV Editor Docked, you could have a layout that is just the UV Editor if you don't want the 3D also present (though I recommend it)
2. Use the Marking Menus instead of Hotbox (personal preference, but I find Marking menus way faster) The marking menu for creating UVs is shift > right click > gesture up
3. Use the UV Toolkit instead of Hotbox (I also think this is faster than using the hotbox, but again, preference)
4. Keep the options window somewhere it's not overlapping with the UV editor
One of the nicest things about Maya is that there are tons of ways to access every feature (hotkeys, menu bar, marking menus, hotbox, etc...) so it sucks the one you prefer is broken, but I suppose all you can do is submit a bug report and choose one of the other options for now.
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