YouTube not asking for data?

Question

YouTube

I am using Google Chrome. When I use the search and everything else in the task manager, it shows that WI-Fi is receiving and sending data.
When I use YouTub without minimizing the browser, everything is fine. But when I minimize Chrome with Alt+Tab and go back to view, the video doesn't load. In the task manager via Wi-Fi, sending and receiving are zero.
If you do not reload the page, then the video starts to go after 30-450 seconds.