+1 here as well. I see that the calendar account is connected, but the actual calendar cannot be viewed online or in the desktop app. I can see it fine on my android app. It doesn't help when I'm at my desk though and I can't see personal appointments (google) when trying to set up work things (outlook).
The problem is it's like outlook online and on the desktop registers that it's connected to my gmail calendar, but there are none of the gmail calendars underneath to select. I've done all of the steps suggested, and unlinked and relinked. This is only online and desktop. The app on my android is fine.