Basic AWS Config S3 set-up

I am just getting started with using AWS Config. I have followed the instructions for manual set-up here - https://docs.aws.amazon.com/config/latest/developerguide/manual-setup.title.html - and am initially just trying to log configuration changes to S3. In the configuration screens I had it set up a new S3 bucket and set it to log all events for US-east-1. Having set it up, I proceeded to make some minor configuration changes - I launched an EC2 instance and then shut it down. In the AWS Config dashboard I see events in the "Configuration Items Recorded" graph at the time I was using the EC2 console, and the "Change Notifications Delivery Failed" graph shows no activity for that time. However, I do not see any entries in the S3 bucket associated with the changes. The AWS Config set up appears to have set up the new bucket correctly but the only entry/object I see in it is named "ConfigWritabilityCheckFile". That file's time stamp corresponds to when I was setting up the AWS Config general settings. I checked the bucket permissions with this documentation - https://docs.aws.amazon.com/config/latest/developerguide/s3-bucket-policy.html - and the permissions seem correct - which is not surprising because I picked defaults and the syste should have set things up correctly.

How can I further research what is going on here or is there something I missed?

Thank you.