Sorry I came to this late. Yes Tahir, that really is the situation with shared calendars in Office 365. They just don't have their act together yet.

In fact, I asked this question too!

I spent WAY more time on it than I should have, and came to a simple conclusion: it's not possible.

MS has done a lot of good things in recent years, but they're still making boneheaded decisions all over the place. At a surface level, everything looks good. But once you start the deep dive you realize how f'ed up things are.

I still tell many businesses to go with Office 365, but I make sure they know of the limitations (as I become aware of them myself). Sometimes it's the best option for what they want to do, but it's still annoying most of the time.