I am using old samsung tab s 8.4. Maybe it has peculiar aspect ratio because all of my streaming videos has black bar on top/bottom. Few years of streaming videos this way has made my screen to have light burn-in (top/bottom brighter than the rest. Right now only detectable using screen diagnostic tool software). I don't want this problem to get to a point where it is clearly noticeable.

Tried everything, and this is the only one that worked on all of my streaming sites by force-stretch the video to full. Genius work !