The shortcut of Ctrl-left click on taskbar mini to launch the main app window is not setting focus to the main 1P window. So if you try to enter master password or start typing search criteria, the input goes nowhere. When you right-click mini icon and choose "Open 1Password app" the focus is set correctly.
1Password Version: 6.6.439d
Extension Version: 188.8.131.52
OS Version: Win10 1703
Sync Type: Every single type you offer