Files Not Appearing in S3 File Storage Gateway Bucket

I created an AWS S3 File Storage Gateway and mounted it to a Linux server on-prem. On that same server where the file gateway is mounted I have a separate NFS share mounted. My goal is to copy files from the NFS share to the file gateway share - so NFS mount to NFS mount.

For some reason though the files copy over (if I am on the Linux server I can see them in the directory I created) but I can't see them in the S3 Bucket when I access via a browser. The files I am copying over are VM images and I am copying the files over using a shell script.

I tried waiting a few hours to see if the file would appear in the bucket in the browser - each one was 3-4gb and it was three files total, but nothing shows up. Any idea what the issue is or what I'm missing here?