Chatting with remote computer on my account (TV 14)

I have installed Teamviewer on my customers computers (150) and added them to my account, with password-protected remote management enabled.

I was able to send messages to these computers and customers were able to directly view the message and directly reply to it (TeamViewer 7).

Now,  in Teamviewer 14 (licence Business) just shows a message notification, and when they try to read it, Teamviewer asks for a login. Is there a way to restore functionality?

If not, what last version can chat without login to account?

Thank You