Embedded video thumbnail in post changes when using "go back" action on browser

We have a page with multiple posts with embedded videos that display nicely on the main page (image 03). As expected, the video plays in the thumbnail of each post. The odd behavior is that when a user selects any post to read and then uses the “back” button to return to the main page, all video posts on the page display and link to a single video (image 04). Please advise how to fix this.

Thank you.