I have a stable/solid IPTV provider, they're convinced there's no issue at their end.
I use Nvidia shield TV, ethernet connection to internet (70mbps service). I still get IPTV buffering issues often enough to be irritating (no issues with Netflix or other apps used to stream shows).
I use Tivitmate pro but find even if I switch to my IPTV providers native app - same issues, same channels.
When buffering occurs I can jump into a speedtest and there seems to be no issue on speed.
I recently changed routers, no real change.
I'd really appreciate any suggestions.
Start a stream, login to your router and check the resource table. It'll have tcp connections, look for an IP using port 25461. Traceroute that ip and see where the latency is, your side or theirs.
Or do the easy route. First try a vpn, than another provider like the others suggested if still having issues