Thanks.
Well... I am doing exactly what error description says.
I open avast one. Freshly installed. After a phone reboot. I go on the account section of the app. I try to login. It shows a processing animation, then error 1005 fail to connect.
It is right login and password. If I put wrong info, it instantly recognize wrong login.
I wonder if it's avast licensing having issue or if an old piece of Android parameter that had been set wrong for One by a previous Avast app installation.