I have VS Community 2017 15.9.3 which I use with Unity.
I have a window layout saved where the results window for 'find all references' is on the right of the screen.
If I apply my window layout (Ctrl + Alt + 1) and 'find all references' then the window appears on the right.
If I then close the window, and 'find all references' again, the window appears in its default position on the bottom.
So I have to hit Ctrl + Alt + 1 before I 'find all references' every time.
This is slowly driving me insane.