Is there finally an actual fix now for the app not finding the device??? It's the only way, albeit clunky and inconvenient, I have to watch using headphones. And YES, phone and TV are on the same WiFi network, everything's updated, everything's been restarted a hundred times. Like others have said, this is a recent problem.
I can't connect my phone to the TV it's not working it said it can't find the device and I need to check my internet and it works on every other device and they just asked me to silly question that doesn't solve our problem I need help it is 3 am and I'm still trying to figure out this problem and it doesn't often and I'm tired of it help
The most likely resolution is to turn off (Access Point) AP Isolation within your WiFi router settings - login to the router admin and begin with Wireless Settings / Advanced or Additional Settings or run through the numerous admin settings grouping screens specific to your router looking for AP Isolation and disable / uncheck the option.
Access Point AP Isolation is a security feature that when enabled prevents different devices logged into the same WiFi network from seeing / communicating with each other while still able to access the internet, so for a home network with WiFi login credentials this is not likely important. AP Isolation is specifically intended to prevent the type of communication that is required for Roku remote apps to discover and communicate with your Roku device.
I wasn't able to use the Roku app keyboard / remote control for years until I decided to research and change dozens of possible WiFi router settings. Some of the non-Roku remote control apps even allow you to enter the Roku network IP address to connect directly to the Roku device rather than discover the device, but the app communication still wouldn't connect. Roku really needs to include mentioning AP Isolation in their main setup as well as trouble-shooting help files.