Roku has a feature called Bandwidth Saver to help people with data or bandwidth caps. After 4 hours without remote activity, you may be asked if you want to keep streaming. Click Keep streaming to continue playback. If you do nothing, Philo will close.
You can click Don't ask for this channel to disable the prompt for Philo. Or, you can disable the prompt for all your Roku channels:
Press on your Roku remote.
Click Bandwidth saver.