FTP over explicit TLS issue in cpanel server

[Allen Fan]

I am facing issues with connecting to the FTP of all websites in cPanel whenever I use FTP over explicit TLS. I use Filezilla ftp client to connect to FTP. Whenever I connect using plain authentication, there is no issue, but while trying to connect to FTP using explict TLS, the connection establishes but the directory listing fails with the following error

Error: Connection timed out after 20 seconds of inactivity
Error: Failed to retrieve directory listing

I have enabled Passive Port range in the pureftpd.conf and also the Firewall, but the issue remains. What is the solution?