Can't add Outlook account, "accept" grayed out

I'm told in Microsoft's help article that this issue was fixed in Version 2003 Build 12624.20382, however I am on the current Office 365 deployment and still can't it to work.

When I try to add a personal Gmail account into my Outlook profile, it pops up a Google login and presents a set of permissions to be granted, however the "accept" option at the bottom is grayed out and can't be clicked.

The document recommends changing default browser, but this seems to make no difference.

Anyone else experiencing this, or able to guide me please?