UserAgent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.110 Safari/537.36

Steps to reproduce the problem:
1. Boot to OS.
2. Download Hangouts App form Chrome Web Store.
3. Video chatting via hangouts. 
4. Find Image of video will flash blackscreen 1~2 times during video chatting via hangouts.

What is the expected behavior?

What went wrong?
Image of video will flash blackscreen 1~2times during video chatting via hangouts.

WebStore page: 

Did this work before? N/A 

Chrome version: 71.0.3578.56  Channel: n/a
OS Version: 
Flash Version: