My xbox 360 account can't connect to xbox live (error code 8015190A) but my Xbox One can....

As the Subject says: I can't sign into my xbox live account on any 360 console. I have in my possession two xbox 360 consoles and have cleaned the cache on both in hopes of cleaning some file corruption, made a change to my avatar in an effort to re sync the account, and various other things found on this community section. No one seems to have quite the problem i'm having and i am a little lost.

Microsoft doesn't seem to want to make calls available for such a problem and their website is very difficult to traverse however i have a potential lead.

- did signing into the second xbox 360 console act as a security breach and have microsoft locked my 360 account until i can somehow verify it is me?

- counter to that point, i have registered the console serial number to my xbox.com account.

i mentioned the error showing up as 8015190A and have followed the instructions there several times so please understand that it doesn't help.

I would also like to stress that it appears to be the account and not the console. The 360 can log other accounts in, just not this one. Also stressing that my xbox One works fine but that backwards compatible games give me the same issue.

thanks in advance for any feedback.

:)