I’ve used a couple of third-party controllers on both iOS and Android with decent results. The key has been a clean setup routine: put phone and player on the same SSID (not guest), temporarily disable VPN/Private Relay, and grant local network permission when prompted. In the middle of those steps, the Roku remote app is not working. This is explained by a simple checklist that mirrors what I do. After that, I open the controller app, let it auto-discover, and if it stalls, I re-pair from the device’s settings before touching the router.