If I drag World Outliner panel from Editor to make it standalone, the actor is not focused on in viewport when I selected a Actor from World Outliner panel. It works fine when putting World Outliner panel back in the mainframe of editor. I see there are no focus indicator(a little yellow line hightlighted on the top on tab name) on viewport under both of those situation.
I had happen too that a few minutes ago.
push “F” then couldn’t focus.
The editor close and open but same.
but later, could work fine that left+right click of mouse.
I don’t know cause it occur. I tell that could know that.
I hope this will help you. 