Ubuntu 17.10 - clean install
In older versions of Ubuntu (and in other operating systems, such as Windows), pressing Alt-Space opens the Window menu (the one that gives access to window options such as minimize, maximize, move window, etc). This is still true in Ubuntu 17.10. However, once that menu is open, it does not appear to be affected by the keyboard - for example, in previous Ubuntu versions, pressing Alt+Space, then M would minimize the window, Alt+Space, then X would maximize the window, etc.
Not in 17.10 - I haven't found a keystroke that will activate any of the menu items (I can use the arrow keys to highlight the items, but Enter doesn't select the item, nor does there appear to be an assigned accelerator key - such as M or X - to select the option).
Is there somewhere that these kinds of things can be set, or am I missing something blindingly obvious? (I know about, for example, Super+H to minimize - but that doesn't seem very intuitive to me, and would necessitate a learning curve to use - whereas the old standard keyboard shortcuts Alt+Space, M is well ingrained into my habits)...