Enable it under services

SSH to your switch and log inn. Type enable To se diagnostics for port 1 type sh cable-diagnostics interface gigabitEthernet 1/0/1 ? for more information.

@PavelV I don't think you need to connect something, but give it a try. enable WAN/LAN1 on internet and se ;.)

@PavelV You don't need to disable on LAN, just enable WAN/LAN1 in internet section and apply.

You need a switch with IGMP Snooping https://www.altibox.no/privat/kundeservice/tv/kobling-via-switch/

@Libik This is a beta firmware but I have less problem with this update than before. get it from support.forum@tp-link.com But less memory and cpu vas only temporary, I have to restart router on time...