Teamviewer starting on boot but not providing access

I have my Ubuntu 17.10 setup with Teamviewer 13 set on Start on System boot. It was working fine.

I reboot my system, and a minute later I see Teamviewer site has signed in. But when I try to connect the remote system window doesn't open. Teamviewer is showing that system has signed in but the window isn't opening. The remote terminal user hasn't signed in to the system. Is it necessary to sign-in to let Teamviewer take remote access?