Users not prompt to save to local drafts when checking out a document

In our environment (IE 11, Office 265 and Office 2013) Users are not prompted to use a local drafts folder when checking out a document. I've narrowed this down to be an Office / IE issue. I've tried various settings in Word (File-> Options -> Save -> and tried both of the options).

I've double checked that the addon in Internet Explorer is installed, enabled and allowed for all sites

Any ideas would be greatly appreciated.