If we tested using a Smart Speaker or the Google mobile assistant, it would bring back the wrong results.

Resolution:

Undeploy the Alpha Action, and deployed deploy the Action (via the actions console).

Best Practices:

Whenever you add intents or slot values in the project, you should publish the interaction model to Google dialogflow via the Experience Manager.
After deployment, the changes will be reflected for “Admin“ and “Developer“ roles only. It will not be reflected for Alpha and Beta users for the skill.
For the changes to get reflected for the Alpha and Beta users in the skill, we need to do the version release for the Alpha and Beta section in the skill.