We've confirmed that all systems are back to normal with no customer impact as of 06/11, 12:26 UTC. Our logs show the incident started on 06/09, 08:26 UTC and that during the 2 days 4 hours that it took to resolve the issue some the of customers experienced missing alerts in azure portal globally.
Root Cause: The failure was due to one our back end services.
Incident Timeline: 2 days 4 Hours - 06/09, 08:26 UTC through 06/11, 12:26 UTC
We understand that customers rely on Log Alerts as a critical service and apologize for any impact this incident caused. -Syed