New devices only receive "Enterprise Default Profile" instead of default profile

kvkowas this solved? I am reading this and it looks familiar to a similar case. Can you confirm if you have Microsoft Intune as your MDM solution?
It looks you have done step 3 

"A default configuration is created. A screen appears with basic information about the configuration. Intune will automatically apply the default configuration to any zero-touch enabled device that's without an existing configuration."

What that basically makes is that Intune default configuration from iframe will apply even though on your customer portal you have a default one. In order to deactivate this you will need to go here inside Intune:

Devices > Android Devices > Enrollment > Zero-touch enrollment 
If you click there you will see an option to Unlink. 
That should solve your issue, and the configuration apply will be the one set as default on your customer portal if a device is added.