Hi @Gyst, it looks like the movie is getting constrained by the 960px container, if the movie is moved out of the container into a full width section and set to 100% width, then the bars should go away on top and bottom.
I would also set the max width to be 1080px on the video, if that was the original video width.
Try that and see if it helps.
Here is another article that may help: https://wistia.com/blog/remove-black-bars-from-online-video
At this page: https://pacoup.com/2011/06/12/list-of-true-169-resolutions/, it shows the resolutions for 1920x1080p highlighted in green. If the video is set to those dimensions, then the bar will also go away.