Sound notifications don't work correctly in Chrome 69 (maybe in newer Chrome too).

When notification window appearing, there is no sound played.
When Chrome extension automatically reloads Zabbix Main Panel page after X seconds, there is no sound played.
When pressed button "Reload page" in Chrome no sound played.
When pressed F5 button on keyboard, notification sound starts playing.

But sometimes (very rarely) sound start playing without page reloading. Very strange behavior...

Steps to reproduce:

1. Open Zabbix main monitoring panel
2. Wait for float notiication panel appearing and no sound playing
3. Press button "Reload page" in Chrome, there is no sound playing (you can do it many times)
4. Press F5 button on keyboard, notification sound starts playing.