Amazon S3 Upload Lag

I recently started hosting a site on S3, and I've been having issues with lag when uploading files to buckets. By lag, I mean 24 hours. Any idea what's wrong? I followed AWS' guide to hosting a static website. From some research, it may have something to do with Cloudfront not working properly?

P.S. I'm new to AWS and website-hosting in general.

Thanks, Mike