Connect via FTP with FileZilla issue

Hi, It's been a while since I've used FTP and updated my website. It's always been easy to log in with my ftp address, user name, password, and (optionally) port 21. FileZilla says I'm connecting, but then disconnects. I'm sure it's something simple. I have no special situations. I just want to connect to my cpanel main site. I used to be able to do ftp://ftp.example.com, but that doesn't work anymore. I guess things have changed. Any help appreciated!