VLC issues vs SS IPTV

[Hauslabuland]

I know it was probably discussed multiple times but I've finally had enough. Most of the channels I watch are working fine in VLC and SS IPTV but some channels just won't stop buffering in VLC and work just fine on my smart TV https://100001.onl/ https://1921681254.mx/. Both devices are on the same network, I used all the best practices for using VLC with IPTV. What could be the issue here?