Outlook.com lost connected email account?

I configured an email address to be managed through outlook.com. I did this a year or more ago and it worked fine. On Sunday, I noticed I wasn’t receiving email on the account anymore. When I went to settings, had no additional accounts listed. Basically, the setup for the other email address was completely gone like it was never there. I’ll set it back up but was courious if this happened to anyone else or why it might have happened?