Configure QQ Tencent Calendar with MacOS Calendar

Hi,

I make consulting for a Chinese company and they gave me an Tencent QQ exmail.qq.com email account. Email sync works perfect, but it does NOT synch the calendar part of the server on my latest Macbook with latest MacOS BigSur.

On the other hand, it DOES synch my calendar on my iPhone with latest iOS 14.3 (see screenshot) ... and the calendar works on the iphone perfectly... I put the same setting on the MacOS calendar configuration but it does not work... is there something I need to consider? Is there a way to "mirror" that specific calendar i can update from the iPhone into the Mac so I have all my calendars unified?

Attached is a screenshot of my Calendar settings on the iOS iPhone...

Any tips and tricks and comments are welcome.

Thanks