Successful log in to Microsoft account / outlook despite using Microsoft authenticator

Im sorry if this is the wrong subreddit, I don't know where to post this and I'm really shaken up. Today I got an email stating " unusual sign-in activity " from another country, the IP says that the hostname is " virtua 'dot' com " and the whole thing about if this wasn't me, to secure my account. I also got a notification about it through my authenticator app. I go to the Microsoft security page and it says " successful sign-in. Resolved unusual activity " Did they ACTUALLY sign in to my account and have access to it for that minute until I secured my account? How would they be able to if I use the authenticator app? I changed my password, cleared my cookies, and turned on the 2FA with a generated code. Am I safe? What else could I do?