I'm experiencing a 1-2 second sound lag whilst using smart view from my galaxy s21 ultra (and also from my previous s10 plus) to my Samsung ue55h6400. - This makes watching/casting YouTube etc a horrible experience. I don't have WiFi and rely on my unlimited mobile data plan. I don't think this is relevant though as my 32" Samsung in my bedroom works perfectly every time. Any advice would be much appreciated.