I can’t connect to Xbox Live when trying to play Xbox 360 games on my Xbox One

So I have done quite a bit of research regarding the backwards compatibility issue with Xbox 360 games on Xbox One, and nothing seems to work for me. At the end of the day, I can’t sign into my account through the Xbox 360 window. I’m signed into Xbox Live on my normal Xbox One account, but I’m unable to play online games like Black Ops 2 because I can’t connect to Xbox 360 Live.

So far I have tried hard resetting my Xbox, disconnecting/reconnecting my router, clearing local Xbox 360 storage, changing my IP and other info from automatic to manual, deleting/reinstalling my account, signing in with another account … you name it. Nothing seems to work for me.

I can play other online games fine but it just seems my 360 games will not connect to online servers. What could be wrong?

:)