Triggering an automation when TV state attribute switches to Netlix - Need help

I’m trying to trigger an automation based when I open the Netflix app on my TV. The state trigger just doesn’t seem to work. Below is what I have so far for my automation. I have tried changing attribute to “source” but that didn’t help. I even tried removing attribute and just having the trigger as TV state changing to “on” and no result.
Any advice?
EDIT: changing the TV’s state to “on” ended up working after all for the trigger. Still no luck with the Netflix source though.

trigger:
  - platform: state
    entity_id: media_player.sony_bravia_tv
    attribute: source_list
    to: Netflix
condition: []
action:
  - service: media_player.volume_set
    target:
      entity_id: media_player.sonos
    data:
      volume_level: 0.3
  - service: script.activate_alexa_actionable_notification
    data_template:
      text: >-
        If youre watching Netflix, would you like me to turn the lights to
        cinema mode?
      event_id: actionable_notification_netflix_lights
      alexa_device: media_player.sonos

Look at the attributes in the developer tools when you change the Bravia source to Netflix. With my Bravia, HA can tell it to change to a specific source, but if the source is an app like Netflix there is no source attribute reported back - just “media_title: App”

If Netflix is the only app you use, that media title attribute could be used for a trigger. But it doesn’t allow distinguishing apps. Maybe see what happens when you play actual content - that might give you an attribute you could work with.

That makes sense. Mine doesn’t report back source attributes either and media title is just “app” regardless of the app used or the content playing or not. I use several apps on the TV but only really want this to trigger with specific ones. I guess I have finally found something I can’t do with HA!

Just a thought: does your Bravia have built in Chromecast? If so, check if any attributes come up in the media player entity for the Chromecast when you use Netflix or the other apps you use. From memory, the YouTube app actually works via the Chromecast platform but the Netflix app doesn’t - so the presence vs absence of info in the Chromecast states maybe could be used as an automation condition?

My biggest beef with the Bravia is it reports volume but doesn’t let you set volume from HA to a set level. All you can do is increment up or down. I’m not yet game to try my hand at loops to get around that.

So I’ve finally had a chance to look into this, and sure enough, the information shows up on the chromecast entity for bravia TVs with built-in chromecast! I started a program from netflix using the Netflix app in the android TV menu on the Bravia, and the chromecast entity has the following attributes:

is_volume_muted: false
media_position_updated_at: 2021-05-28T07:09:08.788829+00:00
app_id: Netflix
app_name: Netflix
entity_picture_local: null
friendly_name: Upstairs display
supported_features: 21389

I think this should allow the kind of automation you’re looking for, you just need to look at the chromecast entity, not the Bravia one.