deleting a video from my account landing page

It is always best starting with https://help.imdb.com/ vs. Google as Google summaries can be out-of-date or fail to find everything (as apparently here). 

Please see: https://help.imdb.com/article/imdb/discover-watch/videos-faq/GJRQPZZ8AG6RSM63 and specifically:

There is an incorrect video assigned to a title or name page. How do I report this?

Titles and videos are automatically matched by our software. This is usually accurate in 99% of cases, but mistakes are always possible, particularly when two films have the same (or very similar) titles. If  you have found a video linked to the incorrect title/name or a video missing a link to a title/name, please report this to our staff using then following the instructions:

Visit the Contact Us page while logged into your IMDb/IMDbPro account and select IMDb Contributor > I need help and haven't submitted an update > Images & video > Remove/update videos then select "Email" and let us know how we can help.

Hope this helps. 

Is it under “Recently viewed” on your homepage? If so, hover over the video thumbnail and look for a small X or “remove” option. If you don’t see it, open the full Recently viewed page and use “Clear all.” That worked for me. Otherwise, check Settings > Privacy / Your activity.