Shared office 365 calendars not appearing on Mac Calendar but do appear on iPhone calendar

I currently have an Outlook Calendar with work and can get most of it to work with my Mac Calendar. I can see my own Outlook calendars but the Outlook calendars that are shared to me do not appear on my Mac Calendar. They appear with no issues on my iPhone, but I can not get them to show on my Mac (v15.4).

(I've found several question on the community about this in the past but no answers.)

Thank you for any assistance to sort this out.