Your stream doesn't work. The reseller says you must use port 4 on your router. Not ports 1, 2, or 3. Only port 4. You move the cable. It works. The reseller's requirement is fake. All ports are identical.
A British IPTV reseller who requires a specific router port is inventing fake troubleshooting. Ethernet ports on a router are identical. There's no technical reason for this requirement. The reseller is making things up to sound knowledgeable.
The British IPTV services with proper troubleshooting never mention specific router ports. Any port works. The reseller who requires port 4 is either incompetent or deliberately wasting your time.
The IPTV reseller panel doesn't care about router ports. The reseller's app doesn't either. The reseller is inventing fake steps.
The IPTV reseller UK operators who know what they're doing never mention specific ports. The resellers who do are making things up.
Here's a scenario that wastes your time. Your stream buffers. Support says you must use port 4 on your router. You crawl behind your desk. You unplug the cable from port 2. You plug it into port 4. The stream works (it would have worked anyway). You've wasted time and effort on a fake requirement.
The next day, you need to plug something else into port 4. You have to choose. The reseller's fake requirement has created unnecessary cable management headaches.
I've tested router port requirements across dozens of resellers. None have legitimate port requirements. Resellers who claim you need a specific port are making up troubleshooting steps.
An honest British IPTV reseller will never mention specific router ports. You can test this by reporting a problem. If they ask about which router port you're using, they're making things up. If they focus on their service, they're professional.
The same principle applies to requiring specific USB ports on routers or streaming devices. Some resellers claim only certain ports work. It's fake.
A non fake British IPTV service will give real technical advice. Test by asking for help. If they invent fake requirements about ports, they're incompetent.