Why won't my Samsung smart TV work on the guest network?

The short answer

Casting from your phone fails across a guest network. Guest networks deliberately stop devices from seeing each other. That is exactly what this gadget needs to do, so it fails — as designed.

What's happening underneath

Casting and phone remotes stop working.

Source: Manufacturer documentation

Try these, in this order

• • Try the TV on 5 GHz first; if it won't hold the connection, use 2.4 GHz.
• • Move a mesh box into the same room rather than behind the TV.
• • Use the TV's Ethernet port if the router is anywhere near.
• • Check the signal where the gadget actually lives, not where you're standing.
• • Move the router off the floor and out of any cupboard before buying anything.
• • Put the gadget and your phone on the same Wi-Fi name.
• • Restart the gadget before the router — it is quicker and it fixes more.

Setting it up again properly

• • Stand next to your router while you set it up, then move the gadget to where it lives.
• • Put your phone on the 2.4 GHz network name for the setup, or use one name for both bands so the phone can follow.
• • If your router splits bands into two names, turn the 5 GHz one off for five minutes rather than fighting it.
• • Turn mobile data off on your phone during setup — some apps quietly use it and never find the gadget.

When it's worth spending money

If evening buffering happens on every device, it's the broadband. If it's only the TV, it's coverage.