some media contents and GIF pictures aren't played automatically

[tmdwns7809]

Steps to reproduce

Open these sites https://www.fmkorea.com/best/2825628999

https://gall.dcinside.com/board/view/?id=football_new6&no=6808084&s_type=search_all&s_keyword=gif&page=1

Expected behavior

the media contents in those sites are automatically played in other browsers

Actual behavior

it doesn't get autoplayed in reference browser, and in the 2nd web site the gif picture is just dark before i long press the picture.

Device information

Samsung Galaxy Note 9 SM-N960

• Android device: SM-N960
• Focus version: latest version