I use it a little in my holiday home by connecting it to the mobile phone hotspot and I experience the same problem.

This is indeed the case, but I haven't yet found out whether it's faster. I'm not so happy with the Philips TV in other respects either, you're tied to the apps that are on it, you can't install other apps yourself and Airplay also leaves a lot to be desired. So antenna cable to Sunrisebox, then it works. The TV is advertised as a Smart TV, but that doesn't mean anything if you take Samsung as a comparison.