It's been months since I bought my TCL 43S425 43in 4k ultra hd smart roku tv and I still can't get certain things to work. Airplay, and this gosh darn roku app remote. It doesn't recognize my tv as a roku device. I've tried inputting the IP address and it says there's no roku device at this address. Tried it on Android and IPhone. It still doesn't. Work.
My friend wonders if it's the public wifi of my apartment building. I wonder if it's something more. I can't get it recognized no matter what I do. This tv has issues with outside devices linking to it. What's the deal?
Make sure "Control by mobile apps" is enabled under Settings->System->Advanced system settings. There's two settings that will enable it - Default or Permissive. Try them both. You'll also see "Device connect" there. You'll probably want to make sure it's enabled.
I assume the phone is connected to the same Wi-Fi as the TV.
I have a feeling there's something screwy with your Wi-Fi, but the IP address you want to put into the app is the one shown on your TV from Settings->About. You should probably be happy that you can't connect because if everyone is sharing the same Wi-Fi then anyone would be able to control your TV using the app.