Media Player Commands Not Working

I’m trying to pause a video immediately upon it starting, wait a bit, and then unpause it. It’s kinda-sorta working on my Shield via Android TV’s ADB integration, though the Shield reports “playing” status as soon as I select an item so the “pause” command fires before it’s loaded and thus does nothing (I can tell things are happening, though, because the OSD is visible when the video does load, which wouldn’t happen if no playback commands had been entered).

On my UGOOS A6B+, on the other hand, it’s even more broken. Like the Shield, the UGOOS reports “playing” status immediately, but in this case the “pause” command actually does work…but not until the video has played for half a second or so. I can actually see the state become “paused” in Developer Tools before the video has loaded, then it plays for a bit while its status remains “paused,” then it pauses.

But rather than unpausing after a few seconds, as it’s supposed to, it just…stays paused.

  triggers:
  - trigger: webhook
    allowed_methods:
    - POST
    - PUT
    local_only: true
    webhook_id: #####
  conditions: []
  actions:
  - action: light.turn_off
    metadata: {}
    data: {}
    target:
      entity_id: light.theater
  - action: input_boolean.turn_on
    metadata: {}
    data: {}
    target:
      entity_id: input_boolean.ignore_light_commands
  - action: media_player.media_pause
    metadata: {}
    data: {}
    target:
      entity_id: media_player.emby_embycon
  - choose:
    - conditions:
      - condition: template
        value_template: '{{ trigger.json.Item.MediaStreams[0].ColorPrimaries == "bt2020"
          }}'
      sequence:
      - delay:
          hours: 0
          minutes: 0
          seconds: 5
          milliseconds: 0
    default:
    - delay:
        hours: 0
        minutes: 0
        seconds: 3
        milliseconds: 0
  - action: media_player.media_play
    metadata: {}
    data: {}
    target:
      entity_id: media_player.emby_embycon
    enabled: true
  - delay:
      hours: 0
      minutes: 0
      seconds: 0
      milliseconds: 500
  - action: input_boolean.turn_off
    metadata: {}
    data: {}
    target:
      entity_id: input_boolean.ignore_light_commands
  mode: single