nVidia Shield SubtitleView of Exo Player is not displayed

I am developing and android TV app using the google’s InputService TV standard with ExoPlayer.
The subtitle of the player for some reason is not displaying on the nVidia Shield device (Android 8.0). I’ve tested my implementation on multiple devices and works well except the shield. The close caption settings are enabled.
Does the shield require any additional settings / coding in order to display the subtitle view?

NOTE: I’ve created a layout capture and I can see the subtitle view attached to the player view in the capture.