Canvas and orthographic camera

Hello,
Im using both of these and I got a problem. I can see my Canvases boundary.35236-canvas.jpg

I tried to switch canvas render mode to Screen Space - Camera and attach to my main camera, but I can still see the boundery on the edges of the screen. All elements in the canvas like text, panel or buttons works correctly as they should.

Sounds like a gizmo thing. Does it actually show in a build?