Ok, so I would first verify that the automation is indeed being triggered, as a sanity check. This is simple to check, if you go to the dev-state page (<>) and go to your automation, you can see the last triggered time.
There’s no chance that this automation has a duplicate alias of another automation, right?
Once you know 100% that the input boolean is triggering the automation: You said that you can trigger each individual action on it’s own. Is that using the same format as you use in the automation? For example, go to the dev-service page, and manually trigger each action using the service data the same as in you automation. IE
Service: switch.turn_on
Service Data:
{
"entity_id": "switch.20146435807d3a4a790c"
}
Then
Service: media_player.turn_on
Service Data:
{
"entity_id": "media_player.living_room"
}
Then
Service: media_player.select_source
Service Data:
{
"entity_id": "media_player.living_room",
"source": "av2"
}
Etc
If every one of those actions works correctly, with the same service data in your automation, then there’s something else screwy. You can try to delete all but 1 action from that automation, and make sure that each action by itself works, then build it back up to all of them, and see where it fails.