Samsung Galaxy A8
website
Samsung internet Browser (based on an older chromium version): No lag
Chrome: Some lag
Firefox: Doesn´t work properly at all, completely broken lmao. I´ve noticed this with some of my projects aswell, they really don´t like Firefox at all. :V
apk
Same as Chrome on website, some lag.
So one could assume that this is maybe caused by some update to Chrome, that hasn´t hit the samsung internet browser yet. What you could try is to change the sprite when "in touch". I tried that and it seemed that the sprite reacts instantly, while the sound is played with a delay. But my delay isn´t as severe as on your side so I´m not 100% sure about it. You could also try older versions of Chromium and see if the issue is solved by that --> in this case Chrome probably effed up something in an update.