Roku remote not staying paired

Since the remote connects to the player using WiFi direct, I'd suggest you install WiFi Analyzer for Android or something similar if you use an iPhone. Then open the app and take note of how many others are using the same channel, log into the router and choose a channel/band with less congestion. If you use service provider modem/router its likely the router is set to defaults that include 'auto' for channel selection. This can cause problems in WiFi environments