I have a problem with caldav sync with thunderbird/Ligthning (Th version 45.3, Lh 3). The scenario is the following

1) USer A defines with zoho web app an own calendar and share it via CALDAV.

2) User B make the same for his calendar

3) User A share on zoho web site the user B Calendar and in this case we have no problem. Following the privileges stated by user B, user A can only view events of B or modify, delete, insert events too

4) Now I use Thunderbird to link the user A Calendar (I'm user A). The link is succesfull and I can full manage my calendar

5) BUT when I link the user B Calendar using the correct URL found in the user guide in conjuction with the calendar ID found in the user B settings details, I HAVE A PROBLEM. In this case the calendar is always disabled (also if I force it to active)

6) I retry the link on another system: the calendar is active, but the events are not showned at all

What I made wrong? there is another mode to see events of both users A and B with thunderbird or similar app?

Thank you for your support 

Best regards