Hi Vitor,
Thank you for your reply, and sorry for my poor explanation. Let me try to re-describe what I run into as precisely as I can.
This happens when I paste to window on 2nd display from the clipboard stored in Alfred. For example, I open Firefox on 1st display and Chrome on 2nd display while Chrome is opened on 1st display also and it's hidden behind Firefox window. I make Chrome on 2nd display focused on and put mouse cursor on it then call Alfred clipboard and do Paste action. At this, Alfred window appears on 2nd display. But nothing happens to Chrome on 2nd screen. What it happens is only that Chrome on 1st screen appears on the top(front) and is focused on. Paste action never occurs.
I understand by summoning stored clipboard data from Alfred, it becomes macOS's clipboard data so I again focus on Chrome on 2nd display and do normal past action (⌘V).
Thanks,