Ribbon Size in office 2016

Question

When I collapse my ribbon Word 2016, so it autohides, everything looks good:

When I pin it, it changes the size of the ribbon:

It does the same thing in Excel, Outlook, PowerPoint, ... How do I prevent this from happening?

Retinal MBP (default 2880 x 1800) with VMWare Fusion (8.0.1). Settings for the screen:

Solution

Looks like Office has a 'Mouse mode' and a 'Touch mode'. For some reason when installing Office 2016 in VMWare Fusion 8.0.1 (also in 8.5), Office thinks it should default to 'Touch mode'.

Chasing it is quite easy (once you know where to look):

1. On the Quick Access Toolbar, Click the dropdown to edit it.
2. Click Touch/Mouse mode
3. Click the new icon to switch between 'Mouse mode' and 'Touch mode'