Web browsers with video playing prevents screen lock

[Greg Gilbert]

This question relates to the reliability of one of our security controls.  We have machine inactivity timeout on PCs and screensaver lock on users set for 15 minutes. We've found that if video is playing in any web browser, it prevents the screen lock from occurring after 15 minutes of inactivity.  Is there a way to prevent the web browsers from causing this behavior?  If there isn't anything currently, could something be added to Edge or Chromium?  Maybe related to the new sleeping tabs feature that is in development?

[#2]

@Greg Gilbert There is a web standard about keeping the screen awake - see Screen Wake Lock API (w3c.github.io). From a user perspective, making the user move the mouse / touch the keyboard / touch the screen every xx minutes isn't a great experience for content consumption. What's the scenario - how could we tell the difference between content consumption where the user is sitting there, and one where the user wandered off? Would love to understand the scenario and where you'd expect this to happen?

[#3]

@Chris Jackson We've seen a number of instances where video and if I'm reading this Wake Lock API correctly, possibly other unknown apps keep our PCs from locking when a user walks away for 15+ minutes.  I believe our CISO would take the option to limit wake locks to 15 minutes if that were an option. In our business, I suspect very few people spend more than 15 minutes consuming content without interacting with the keyboard or mouse, so the trade off from a security vs. productivity perspective would be worth it.  

If there isn't a way to limit the time a wake lock can function, is there a way in Windows to identify what applications or even web sites are using wake locks?  If so, is there or could there be any way we could whitelist applications or sites to allow wake locks?