Web Browser videos stop playing when switching windows on Macbook Pro

When I upgraded to OS high sierra, videos stop playing in both chrome and safari when I change to a new window. For example if I am watching a lecture on one window and while the video is playing I switch to microsoft word on another window to take notes, the video freezes until I return to the video. It is not a slow connection problem as my internet speed is 100MBs and it only started happening after I upgraded. Is anyone else experiencing this or know how to fix this problem?

Thanks