FWIW, I'm able to create an automation that runs a shortcut to start playing podcasts in Overcast when connecting AirPods. It's not super-clear, but you need t

FWIW, I'm able to create an automation that runs a shortcut to start playing podcasts in Overcast when connecting AirPods. It's not super-clear, but you need to set the automation to "Run a Shortcut" from the Shortcuts app, rather than pick a shortcut from the app itself. Try creating a shortcut in the Shortcuts app to play something in Spotify. Then search for "Run a Shortcut" when you're wiring up the personal automation, and then tap the word "Shortcut" in "Run Shortcut" to pick your Spotify shortcut. The proper fix here should be that all the shortcuts should be direct actions.