Do you use VPC endpoints for S3? The next sentence explained failures I observed with S3: "However, access to Amazon S3 buckets and DynamoDB tables via VPC Endpoints was impaired during this event."
I could not modify file properties in S3, uploading new or modified files was spotty, and AWS Console GUI access was broken as well. Was that because of VPC endpoints?
"Customers also experienced login failures to the AWS Console in the impacted region during the event"