When a Custom Activity in Journey Builder tries to POST to the app's external API endpoint and gets a 400 error, what happens to the subscriber's flow through the journey?
- Does SFMC retry the API call a certain number of times? Indefinitely?
- Does the subscriber get ejected from the Journey?
- Do they get permanently stuck in the custom Journey Builder Activity?
- Or is the error simply logged and they move onto the next step? And if so, where is it logged?
To be clear, this is asking about the call SFMC makes to the host of the app (SFMC->Heroku) NOT the call the app makes to SFMC (Heroku->SFMC).