Your video autoplays every single time you load the page. It does not autoplay for somebody arriving for the first time, and there is no bug in your code.

Chrome has been keeping a score on you, per site, and you have been raising it all week.

The score is real and you can read it

Chrome's autoplay documentation states the rule plainly. Autoplay with sound is allowed if "The user has interacted with the domain (click, tap, etc.)" or, on desktop, if "the user's Media Engagement Index threshold has been crossed, meaning the user has previously played video with sound."

The Media Engagement Index "measures an individual's propensity to consume media on a site", and Chrome calculates it as "a ratio of visits to significant media playback events per origin."

A playback counts as significant only when all of these hold:

"Consumption of the media (audio/video) must be greater than seven seconds."

"Audio must be present and unmuted."

"The tab with the video is active."

"Size of the video (in px) must be…