EC2 Instance Shutdown by SystemD event "Power key pressed" without any inform in advance.

On Jan 04 12:00 GMT, our EC2 t3a.medium instance placed in AZ ap-southeast-1c Has been shutdown (and kept down not restarted -- even Auto-Recovery feature has turned on) from the Physical (or Virtualized) with SystemD event "Power key pressed" but without any inform in advance from AWS.

Can anyone one confirm that this issue is the cause from AWS datacenter or has any notified information to share with us?