When scrolling on Android system, a white block appears on firefox browser. May be it's a broken website's styles, but this appears only in Firefox browser. On Windows system no problems with this thing at all browsers. It happens only in mobile Firefox browser. * Android 9 - Asus Zenfone Max Pro M1 First screenshot made on Firefox on Android 9. Second screenshot made on Opera Touch on Android 9. Third screenshot made on Firefox (Developer Edition) on Windows 10 (in testing service with Android user-agent).