An action that exists on a Child will always override a Parent action of the same name.
Child Actions override Parent Actions with the same name Even If The Child Action Is Disabled!
This is especially important regarding the Gigya _default Challenge which exists on all sites. If your SSO Group utilizes Gigya Default Actions, these Actions MUST be configured at the individual Child Level. See Loyalty Configuration and Administration - Exporting GM Settings for how to streamline the configuration process.
Recommended Best Practice is to always create uniquely named Challenges and Actions at the Parent level for use throughout the SSO group, if all children will use these same settings.