If you see the TV (images) then IGMP proxy is probably set correctly.

If you get a link-local address (169.254.0.0) that's probably because no DHCP server is running on that network. Double check the VLAN assignment for the port you're supposed to get the IP address from.

En fait les options DHCP à configurer dans le contrôleur, c'est "que" pour le serveur DHCP, pas pour le client, donc cette partie la est toujours nécessaire.
Honnêtement, je n'ai pas trop compris l'intérêt de "Added VLAN tagging...". A priori ça fait en sorte que au démarrage il n'ai plus besoin du contrôleur pour préconfigurer le VLAN sur le WAN, mais je n'ai pas poussé les tests plus que ça. Je crois bien que même avec ça, les options "wan-interface" soient toujours nécessaires pour le que le port-forward et IPSEC fonctionnent correctement.

Je suis a jour sur le firmware, tu peux y aller, mais a ma connaissance pas de simplification encore.

Well this is quite strange.

The TV works perfectly now, but when its on, no device gets assigned a correct IP, The other strange thing I noticed, when the TV is on, all LED ports are blinking at the same time.

Here's link so you can see this happening:
https://www.dropbox.com/s/mp8tk21708yfc07/2018-10-01%2021.05.17.mov?dl=0

Do you think it would be an issue because I am using two switches to connect the TV to my USG?

I'll attach a picture of my network below.

I managed to get it working! New devices can connect to the network while the IPTV is on now. This time, I provisioned the USG using jaydee99's config file. The only difference I made was assigning a VLAN to the TV network, and tagging the switch port to use that VLAN. I also enabled IGMP snooping as you suggested. So TV and Internet are working perfectly right now

The final thing I need to configure is IPv6, which might be a challenge since a lot of parameters already exist in the gui. Did you modify the IPv6 script to get yours working?

So I think I am close to having the IPv6 working. Here's what I have done so far:

In the controller GUI, I have made these settings.
set firewall ipv6-name WAN_IN-6 rule 3003 action accept
set firewall ipv6-name WAN_IN-6 rule 3003 protocol icmpv6
set firewall ipv6-name WAN_IN-6 rule 3003 description "allow ICMPv6"

set firewall ipv6-name WAN_LOCAL-6 rule 3003 action accept
set firewall ipv6-name WAN_LOCAL-6 rule 3003 protocol icmpv6
set firewall ipv6-name WAN_LOCAL-6 rule 3003 description "allow ICMPv6"

set firewall ipv6-name WAN_LOCAL-6 rule 3004 description "allow DHCPv6 client/server"
set firewall ipv6-name WAN_LOCAL-6 rule 3004 action accept
set firewall ipv6-name WAN_LOCAL-6 rule 3004 destination port 546
set firewall ipv6-name WAN_LOCAL-6 rule 3004 protocol udp
set firewall ipv6-name WAN_LOCAL-6 rule 3004 source port 547

There is an option to run 'before' or 'after' predefined rules. I selected 'after' since I am not sure (I will attach a screenshot).

Finally, I ran this last block in the CLI:

set interfaces ethernet eth1 ipv6 dup-addr-detect-transmits 1
set interfaces ethernet eth1 ipv6 router-advert cur-hop-limit 64
set interfaces ethernet eth1 ipv6 router-advert link-mtu 0
set interfaces ethernet eth1 ipv6 router-advert managed-flag false
set interfaces ethernet eth1 ipv6 router-advert max-interval 600
set interfaces ethernet eth1 ipv6 router-advert other-config-flag false
set interfaces ethernet eth1 ipv6 router-advert prefix ::/64 autonomous-flag true
set interfaces ethernet eth1 ipv6 router-advert prefix ::/64 on-link-flag true
set interfaces ethernet eth1 ipv6 router-advert prefix ::/64 valid-lifetime 2592000
set interfaces ethernet eth1 ipv6 router-advert reachable-time 0
set interfaces ethernet eth1 ipv6 router-advert retrans-timer 0
set interfaces ethernet eth1 ipv6 router-advert send-advert true


I commit and save, then restart the USG. Internet and TV still work after the restart (thankfully)! But when I ping6 google.com, the CLI says 'network not reachable'. I am not sure what I have done wrong here :-/

Yes, it looks like it: