AT&T: Irritated

Check this link for a possible solution of connection issues:
https://support.xbox.com/en-AU/xbox-one/networking/connection-solution

That didn't help and to make it even more fun, the content in my online vault on MW3 is missing.

Hmmm. OK. I want you to do the same steps that I layed out, but we are going to add one to it. If you have a hard drive then I want you to re-seat the drive. Turn the console off, then remove the HD. Turn the console on and let it boot to the home screen.
Then turn the console off, and re-insert the hard drive. Make sure it is snug in the hole. Finally turn the console back on.

Once that whole process is done, go through clearing the system cache and downloading profile. As a matter of fact, before you download the profile you should remove it from the console. Just make sure that when you select the "Delete" option on your profile,
select the option for "Delete profile only" instead of "Delete profile with items". That will keep any data you have intact.

Hi there Tahki. Sorry to hear about the issues. The outage yesterday left a lot of profile problems in its wake. That being said, I had not seen any problems with people's saved games being deleted. There might be an issue with some corrupted profile data.
I would suggest doing two things to try and clear that up.

- 1st: Clear system cache (Settings > System > Storage > Y button on your hard drive/MU > Clear systme cache). That won't delete anything except for some install files and junk files.

- 2nd: Download your profile. Re-downloading your profile overwrites the profile that's on the console with the profile data from the Xbox LIVE server. That way it'll make sure that your profile data is fresh.

Alright. It is absolutely time to contact LIVE support. There needs to be an escalation done RE: your online content. They closed about an hour ago, but if you call 800-4MY-XBOX in the morning they can get the ball rolling on it.