File Poller on S3 Only Output on Change

In the documentation, the section “Only Output on Change” mentions that it runs if there is a change in the contents of the directory. Is this strictly the timestamp of the file(s) based on the pattern or are the contents of the file checked somehow as well?

I have tested changing the contents (which in turn changes the timestamp of course) on a local file directory and it works without issue. However, when I test on S3, generating a new file but with the same contents, the File Poller does not seem to detect the change.

Update on this. It looks like it is just reading the meta from the file and there are some required S3 permissions missing as the pipeline works locally but does not detect the change on S3. Opening a support ticket. Thanks.