Screen saver blocked by embeded video

When reading the New York Times in Chrome, in a window (not full screen), I went away leaving the page open. When I returned, hours later, the image was still on the screen, the screen saver had not engaged at 10 minutes, and therefore the machine had not locked itself, and the power saver features (monitor off) had not engaged. The clue was that one of those continuous free-running videos embedded in the page was partially on the screen. This appears to have caused Do Not Disturb to kick in even though nothing was full screen and I was not actually watching any video. If this interpretation is correct it is a serious security flaw in Avast! This is in Windows 7 with free Avast!, auto-updated.

Hi,

Can you try to reproduce the issue with Do Not Disturb turned off?
Could you also test it with Avast Antivirus disabled, please? (right-click the Avast icon in the system tray and select Avast shields control. Select one of the options)