I remember having seen somebody complaining about it, but haven't found the issue in YouTrack:
In Maia keyboard shortcuts (ctrl-(shift)-n, ctrl-shift-f, ctrl-e...) don't work when neither an editor nor any toolwindow is open.
They simply are ignored.
I get annoyed by this many times each day.
Usually when I start to work on the next bug fix/feature I hold down ctrl-f4 until all editor windows are closed.
Also I usually have no toolwindows open at all.
Next I want to open the class I intend to start working on, but immediately get irritated, because ctrl-n does nothing.
A moment's hesitation, then I sigh and grab the mouse.
Could you please fix this regression soon? Thanks!