I uploaded files to the FTP but they didn't show up right away.
This is normal. The servers cache content which can mean that when a file is uploaded to the FTP, it will not always show up right away. It can take up several hours for the content to show up but usually only takes about 10 minutes. The purpose of this change is to serve pages to constituents faster.
If you're engaged in an active edit-test cycle with static content, it's best to get it looking the way you want in a folder on your PC's local hard drive first, then to push all the files (HTML, images, JS, CSS, etc.) to our servers as a single unit.