Unable to update Apple ID

I spoke to the customer support again. This time an attentive guy there was able to point out the issue that is happening with my account.

Apparently Apple has put some restriction on new iCloud email accounts and they cannot be used as primary Apple ID for first 30 days.

They have added the following note in the documentation page as well but it is written in fine text so it goes unnoticed. One has to pay attention to notice it. It says:

"If you try to change your Apple ID to an @icloud.com email address created within the last 30 days, you might be asked to try again later."

I made my @icloud address 2 days back, so I guess in my case I have wait for 28 more days after which I hope I will be able to change my primary Apple ID address. Let's see.

Yes, this blog discusses the same instructions that apple has mentioned and I followed precisely. Still, I am unable to update my Apple ID primary email to my icloud address!

Any idea why this may be happening?

I have not found any help online yet for this error. Maybe not many are getting this kind of error. I don't even know the technical reason why this may be happening to me. This is quite frustrating for me.

RESPONSE FROM APPLE SUPPORT: I called Apple Support today and they gave some vague answer that I am able to login using your icloud address so that is the maximum I can do. I explained them I wanted this icloud address as my primary email ID so that all Apple email will land on this ID but they don't seem to understand. They looked confused and told my icloud address is also my Apple ID because it is listed under 'reachable at' so it cannot be used as primary ID. They told I can only change it to any other third party address but not icloud. I showed them the apple support article which discussed the new option to change third party address to icloud address. Perhaps the support guys themselves had no idea about this new update from apple.