Hey, would you mind sharing the extension you are using? This should not happen and I would like to help fixing it.
https://chrome.google.com/webstore/detail/lipsurf/lnnmjmalak...
I added an ugly workaround, a slide to the tutorial that asks users to go into their flags and allow autoplay without any gestures. Chrome extensions should have better privileges for playing videos, fullscreening etc. IMO but it all needs to be hacked around limiting extensions.