Why does Search Console say my video is outside the viewport when it is visible on the page?

That message is about video indexing, and Google judges the video’s initial rendered position, not whether it looks visible after you scroll around the live page. For this issue, Google says the entire player needs to be inside the page’s renderable area and visible when the page loads. So check the URL in Search Console’s rendered view and look for anything that pushes, hides, or only loads the player after an interaction. Move the primary video into the initial layout, then request another validation after the change. Also make sure the video is actually present in the rendered HTML—Google’s current video guidance says not to rely on clicks, swipes, or typing to load it.