Hello there , my problem its when i put CTR+F it doesnt cover all the screen and a black edge appear up and down someone know about that problem?

Ps:Im recording at 360(My pc sucks)

1. Click on "Test streaming" (or whatever it is in english)

2. Click on "Edit Scene"

3. Resize manually using Shift + Mouse and the "red lines" up, down, right and left.