Thanks for your post.
We apologize for the inconvenience caused. We would like to inform you that the issue you're encountering might be due to the Bandwidth Saver feature. This feature is designed to conserve the device's power consumption by reducing bandwidth utilization when the device is inactive. This might be the reason why your device turns off after 4 hours.
Please note: Some streaming channels employ their own mechanism to cease data usage after a specific period of inactivity. These features will not be affected when you disable Bandwidth Saver.
To resolve this issue, you can go to the settings of your Roku device and turn off the Bandwidth Saver feature. If you need assistance with this, kindly visit our support page for more information and instructions.