Can't download Microsoft Account to my console

So this is the first time we've tried to connect with Xbox live. I'm the parent... I had an existing Microsoft hotmail account. So from my pc, i went online and made sure it was still valid and it was. Then i went online to Xbox.com and created an account
with my existing Microsoft hotmal account, I even picked out a gamertag that my boys wanted. The problem is, now that I'm on the console, i'm trying to download my account so that they can use the gamertag that we created while online. My wireless internet
connection is perfectly fine. But when I try to sign in, the console eventually prompts me to either create or download an existing profile. Here is where my issue is.. it will not recognize my Microsoft hotmail account and pw, which is the SAME email/pw
that I checked on xbox.com. They are both exactly the same. But my console does not recognize this.. it says something to the effect that email and pw are not valid, and has also offered me to input my two step authentication ... which I setup just for
this. I've entered the number from that auto generation key... and it still says it's not the pw. Please help me, we have been trying for weeks and all they want to do is play with their freinds online and i can't do it! i'm so frustrated.

:)

 

Unlink an Xbox Live account from Microsoft Account

I need to delete my Xbox account, but I can't delete my Microsoft account as it is connected to my Windows download and my Office subscription. Is there any way to unlink the Xbox account from my Microsoft account?

 

80150016 error

His profile is linked to his microsoft account, and mine as a family member. It all looks fine on the accounts, I just can't download his profile to the Xbox console.