You open your app. The channels are in one order. You close and reopen. The order is different. Every refresh randomises the channel list. Your reseller's playlist has no fixed ordering. You can never learn where anything is.
A British IPTV reseller whose channels randomise on every load has no sorting configured. The panel outputs channels in database order. Database order changes. Your app receives a different sequence every time. You can't memorise channel positions.
The British IPTV services with consistent ordering have sorted playlists. Channel 1 is always first. Channel 100 is always in the same place. You learn the order. The reseller who didn't configure sorting leaves you guessing every time.
The IPTV reseller panel includes sorting options. The reseller can sort by number, name, or category. A consistent sort order makes your guide predictable. The resellers who leave sorting disabled give you random chaos.
The IPTV reseller UK operators who use their own service would notice the random order. They'd enable sorting. The resellers who never open their own app don't know that channels are in a different place every time.
Here's a specific scenario that prevents learning. You find that your favourite news channel is the fifth channel in the list. You memorise that position. You close the app. You open it again. The news channel is now the fiftieth channel. Everything moved.
You can never learn where anything is. You have to search every time. Channel surfing is impossible because you don't know what's next. The reseller's random ordering has made the guide completely unpredictable.
I've tested playlist ordering across dozens of resellers. Most have consistent ordering. You learn the layout. Some have random ordering. Every load is a new puzzle. The difference is a single configuration setting in the panel.
A sorted British IPTV reseller will have consistent channel order. You can test this by opening and closing your app several times. If the channel order changes, sorting is disabled. If it stays the same, sorting works.
The same principle applies to category ordering. Some resellers randomise within categories. Sports channels move around inside the sports section. The careful reseller sorts consistently within every category.
A predictable British IPTV service will have a guide that stays the same. You learn where things are. That predictability comes from proper sorting configuration. Test it before you commit.