It cant be this, my download connection is 50 mbps. Its weird, i have this new laptop acer swift 3, and it never happend with my old laptop.in your browser's advanced settings, do you have 'use hardware acceleration when available' enabled?
Is your internet connectivity fast enough to support nearly instant play of whatever res video you are watching? (Naturally, watching 1080P videos can take a few seconds to buffer and start on a 20 Mbps connection vice a 480P video...whereas folks with an 800 Mbps connection, by contrast, might not know this struggle....
go to speedtest.net and see what your reported upload/download speeds are...