I have no nice way to clear the selection. I have to move the camera and click on the sky to be able to do anything unless I want to drag around all these selected blocks, which is not common to do after ungrouping.
Well, there could be one hotkey, that could potentially do the trick, and I’m familiar with it. Right now, the current unselect works by pressing the blank space in the Explorer.
I hope they add shift + ctrl + A as the hotkey to unselect everything.
With PluginActions, you can recreate this behavior by binding a key to game:GetService("Selection"):Set({}). Definitely should be default behavior, though.