Earlier today, a number of users observed incorrect usage statistics being displayed by the App Engine dashboard in the Google Cloud Developer Console. Some resources, especially Frontend Instance Hours, were shown with unrealistically elevated usage.
The dashboard has been returned to normal operation and our engineers are investigating to find and fix the root cause of the issue. So far, the results of our investigation indicate that the issue was purely cosmetic, with no elevated billing or quota denials to any user application. If your application encountered quota denials because of this issue, if you later observe elevated resource billing in your invoice for this month, or if you are still observing unrealistic usage in the App Engine dashboard, please notify Google Cloud Platform Support.