After the last update to 55.0.2994.56 (Kubuntu 18.04), there is no focus inside address bar if I am opening a new tab, clicking on the plus icon, however, there is focus inside address bar if I am opening a new tab using keyboard shortcut (Ctrl + T).

Never faced problem like this. What is happening when you do a fresh Opera install without any extensions?

I am using Kubuntu 16.04, after Opera update to the 55.x, I cannot normally use developer tools anymore. I am working with two monitors and I am always detaching developer tools so developer tools could be on one screen and webpage on another.

After detaching developer tools (to be in a seperate window) everything is fine, but when you are trying to move seperated window somewhere it loses title bar (see attached image). It's super annoying and it's hard to work with a bug like this.

P.S. After update to the 55.0.2994.44 the bug is still there.