As the other community member was suggesting you may need to inspect whether the instance has the
preemptibility policy enabled. You can find this option under '
Availability policy' of the VM.
Under the availability policy, you may further need to check whether the instance is set to '
Terminate VM instance' during the time of a maintenance event. It is still possible that the VM instance's maintenance behavior could have also caused this.
Another approach is to check the
logging information (ie stackdriver logs of the affected GCE VM) around the incident time frame to see if there was any error logs reported over there. Using the logs, you can determine whether the issue is related with the platform itself.
Furthermore, you can also refer
this help center article which describes troubleshooting steps that you might find helpful if you run into problems using Compute Engine instances.