Video plays automatically though set to trigger

Without seeing the file, it's not easy to say what is happening.

• When you insert a video, it's set to play automatically.
• If you add a button to play the video, the video will still play automatically despite the button.
• In the video options, set the video to play when triggered. That will pause the video until the play media is triggered. That's assuming you created your own button to play the video.