AWS S3 batch operation with different total objects between buckets

You may have multipart uploads that failed and are still in your buckets. Check out these two articles on that situation. You will have to create a lifecyle rule for each bucket to get rid of these. I would use 1 day for the time period or else you'll have to wait a long time for it to take effect. Storage lens will tell you if you have these failed uploads or not. You won't see them in your buckets.

https://aws.amazon.com/blogs/aws-cloud-financial-management/discovering-and-deleting-incomplete-multipart-uploads-to-lower-amazon-s3-costs/

https://aws.amazon.com/blogs/aws/s3-lifecycle-management-update-support-for-multipart-uploads-and-delete-markers/

You might want to open a support ticket with AWS to get a refund for these failed uploads. I did and they did refund me for them. Be prepared to tell them what buckets and how far back to go for the refund.