Fullscreen mode of video in Safari

Hello!

I have a problem with a fullscreen mode of video in Safari. When I pushing the button of fullscreen on player or pushing key "F", video goes on the other screen, and in the main Safari window opens a search bar like on photo. Every time when I want to watch a video in fullscreen mode. And any button on the video screen doesn't work when address bar is open.

I don't know what the problem. Mac has updated a few days ago on the latest versions of software.

In previous versions of Mac OS I have not this problem.