"Notebooks" menu width

[jennifer taylor]

Howdy folks...I just got a new work laptop with Windows 10 and OneNote 2016.  I made the "Notebooks" menu on the left a little wider than it was (by default) and now cannot make the width narrower!  The cursor changes to the + icon yet it will not drag left to reduce the width; I can only entirely unpin.

What am I missing?

Thanks for your help,

JT

[#2]

And I can now answer my own question...If you close OneNote and reopen it you can resize to make it narrow again.  Crazy to me but there you go!  Only thing I can think of is expanding it to a certain width did an inherent "snap to width" that couldn't be undone before closing and re-opening?