I've noticed that my calender from my outlook.live e-mail (personal) isn't showing up in the meizu calendar app.

But my professional outlook e-mail (business) calendar does show up.

And I can't even add a calendar through the calendar settings.

Why is this and is there a solution?

I do not want to install another calendar app. I just want to use the app from Meizu where both calendars (personal and business) appear.