Notes do not fill the screen in desktop version

[Siz 0]

Using the desktop version, when I open a Note (or create a new one), the Note no longer fills the whole screen.  It is reduced in size and squashed up against the top right corner of the screen.

• underneath the Note there is black boarder with a thickness of about a third of the height of the screen
• and on the right of the Note, there is another black border, with a thickness of about a third of the screen width.

Screenshot attached

If I have the left hand sidebar showing, same thing:  the Note is compressed and sqashed up ataings the top right corner of the frame, with black borders at the bottom and rigfht.

 Zooming in / doing Ctrl + ,  increases the font size but does not affect the size of the Note (so you just get less text showing).

Closing and re-opening Evernote does not help.  Nor does restarting the PC.

Web version is fine.

Any ideas?