Windows 10 Why Do I Get Transparent Taskbar on Bottom when Fullscreen is enabled?

[htprofile]

Hello. So my problem is very weird. When I watch a video or zoom a picture, I can see a very very transparent taskbar on bottom. I tought it was because of the original taskbar then I moved it to te top. The transparent one is still there. It's like a picture inlaid in the screen. I tried to take a picture with screen capture tool but it does not appear.

Here a picture I took with my phone: https://i.gyazo.com/c1d79b3b8fbab251f15b5595d0162a16.jpg

Thank you for helping me fixing this.

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