So I switched iptv servers and it has 4k movies on it, no hdr though but not bad. It buffers a lot on the 4k movies, everything else is normal, and we have 500 megabit per second internet connection. What can I do? Might it have something to do with the iptv box? Or do I need faster Internet?
This is what i would try: try a diff device if available, try a different player (VLC or MX), try a vpn. All you need is a steady 30Mbps-50Mpbs connection to the server to stream 4K and apparently you are not getting it either from your isp or from their server