How to sync read mails to GMail?

How to sync read mails to GMail?

Hello
I am testing Zoho TeamInbox but I have an issue with my connected GMail account.
Whenever I read a mail in TeamInbox or even reply to it, the email stays as "unread" in GMail.

Is this normal behaviour? I thought that with the 2-way sync of IMAP it should send back the read status to GMail.

Thanks