No input Intent does not work on Dialogflow ES

[Joey-Nguyen]

I have a custom intent which handles no user input, and it's recently stopped working (The agent is built on Dialogflow ES without action builder). The intent is attached with an event named "actions_intent_NO_INPUT".

Step to reproduce:
- If the user just says nothing and doesn't respond, Google Home will always say "Sorry, I didn't hear that", and then after two attempts, will exit. It is the default response and my custom intent does not trigger.

If i try create a test agent and use action builder then, the action builder allow me to configure for system itents like "no input", "no match", and it works just fine. Withou action builder, I can not achieve this.
I wonder if there's some changes in the google api and why my intent doesn't work anymore.