Symptoms
When connecting to Implicit FTP (port 990) the connection may be refused or timeout.
Description
Implicit FTP is not supported by cPanel. The is discussed further in the forum post below.
https://forums.cpanel.net/threads/creating-sftp.142921/#post-659449
Workaround
FTP can be set to require encryption in the following location of WHM.
Home » Service Configuration » FTP Server Configuration