Hello! There is a bug (or inconvenient implementation) of the CTRL+ALT+A shortcut (which opens and focuses the Properties window).
When you open the window, other shortcuts are disabled. In particular, the CTRL+tab to move back to the file does not work. That is, there is no shortcut to close the Properties window again.
The same applies for the CTRL+ALT+F and CTRL+ALT+P, however not for the shortcut CTRL+ALT+S, opening the “Snippets” window.
At this point, I push CTRL+ALT+A to open the properties window, I push CTRL+ALT+S to open the “Snippets” window, and then I push ctrl+tab to move back to the file.
However, it would definetly be more convenient if there was a “close properties/activities/project window” shortcut.