How to setup IPTV for UK BT YouView/TalkTalk VDSL on DSL-AC68U?
Copied this From ASUS – https://www.asus.com/uk/support/FAQ/1016388/
How to setup IPTV for UK BT YouView/TalkTalk VDSL on DSL-AC68U?
Here we provide you information about how to set up IPTV for UK ISP (BT/TalkTalk VDSL) on DSL-AC68U
(1) Go to WAN ->Internet Connection, set WAN Type to VDSL and press the “+” to add new element.

(2) From PVC Setting, Set WAN Connection Type to PPPoE. For 802.1Q, Set it [Enable] and set VLAN ID as 101. Then you can fill in your username and password, lastly remember to press OK button.

(3) You will see the PVC summary below.

(4) Go to LAN->IPTV, set as the followings:
Use DHCP routes: RFC3442 & Microsoft
Enable multicast routing (IGMP Proxy): Enable
Enable efficient multicast forwarding (IGMP Snooping): Enable
Remember to press [Apply].

note: If no success and for other models (ASUS) try also setting ‘Enable VPN + DHCP Connection’ to ‘No’ under the WAN option.
Note: No need to set STB port, therefore YouView Box can be connected in any one of LAN ports