Carddav Google contacts sync does not sync from server to thunderbird addressbook

Thunderbird version 85 beta 3 released January 4, 2021
Windows 10

Having problems syncing Google Contacts from thunderbird to server.

I have added a new CardDav addressbook and entered google server and login details.
On creation, the addressbook is synced from server to thunderbird.
A new contact added to the thunderbird addressbook is synced to google contacts server fine (checked in browser).
A new contact added to the google contacts serverside(in browser), is never synced to the thunderbird addressbook.

Manually selecting sync from the thunderbird addressbook context menu does not help.
I see nothing exceptional in the console.

please help me out,
since gContactSync is not working anymore, I see no other option to sync google contacts.