No traffic to Cloudfront distribution

Based on your description, there are several possible reasons why your CloudFront distribution stopped receiving traffic for an hour:

1. Administrative Disabling: Your distribution might have been administratively disabled. This is different from the regular enabled/disabled state you control through the console. When this happens, the distribution appears enabled but doesn't serve traffic, and you might see "Access Denied" errors when trying to modify it.

2. Geographic Restrictions: If you have geographic restrictions configured on your CloudFront distribution, they might have been inadvertently applied or misconfigured during that time period.

3. Edge Location Issues: Problems with specific CloudFront edge locations could affect traffic from certain areas while leaving others unaffected.

4. Origin Server Problems: If your origin server (e.g., an S3 bucket) experienced issues, it could have affected CloudFront's ability to serve content.

5. Caching Issues: CloudFront caches responses, including error responses. If there was a temporary issue that caused errors, these might have been cached.

6. Security-Related Events: AWS might have temporarily restricted your distribution due to security concerns or irregular activity detection.

To investigate further:

• Check your CloudFront distribution settings, particularly any geographic restrictions or security features
• Review your CloudFront access logs for the affected period
• Verify if there were any changes or updates made to your distribution or origin server around that time
• Check if there were any security notifications or alerts sent to your account email

If the issue persists or recurs, contacting AWS Support would be advisable as they can access more detailed information about your distribution's performance and any potential service-wide issues.
Sources
The CloudFront Distribution did not handle requests from outside for two hours 18.01.25. | AWS re:Post
Cloudfront 'Shadow Disabled' and stopped serving traffic | AWS re:Post
CloudFront distributions stoped working after receiving AWS security email | AWS re:Post