HBO Max app for Android TV does not output Dolby 5.1 using a digital optical cable. Amazon and Netflix output Dolby Digital 5.1 as expected. Something in the app is preventing conversion from Dolby Digital Plus to the regular Dolby Digital format that can be transmitted with an optical cable. The other streaming providers have it figured out but Warner developers haven't. Adding- tried all the fixes suggested by hbomax support. They don't work. Time for the developers to take note and look into it.