I've got an excellent provider and a very very good internet connection but still got buffering occasionally on life TV. I use a VPN which is always going to slow things down a bit. I've recently moved to NordVPN and was playing around with the settings last week and started using what they call the P2P VPN under "speciality servers". I'm assuming this is peer-2-peer.
Since then I have not had a single bit of buffering. Nothing, rock solid. Maybe it's a coincidence?
Just thought I'd share, in case someone else might find it useful.
Not every location on your VPN will work perfectly with iptv.. Some IPs work better than others.. You just have to try and see what gives the best experience