AUTH TLS Command blocking the connection to the server

[beastburg]

14:03:04 Status: Resolving address of ftp.XXXXXXXXX.com
14:03:04 Status: Connecting to XXX.XXX.XXX.X:21...
14:03:04 Status: Connection established, waiting for welcome message...
14:03:47 Response: 220---------- Welcome to Pure-FTPd [privsep] [TLS] ----------
14:03:47 Response: 220-You are user number 4 of 50 allowed.
14:03:47 Response: 220-Local time is now 14:03. Server port: 21.
14:03:47 Response: 220-This is a private system - No anonymous login
14:03:47 Response: 220-IPv6 connections are also welcome on this server.
14:03:47 Response: 220 You will be disconnected after 15 minutes of inactivity.
14:03:47 Command: AUTH TLS
14:03:47 Error: Could not connect to server
14:03:47 Status: Waiting to retry...
14:03:52 Status: Resolving address of ftp.XXXXXXXXXXXX.com
14:03:52 Status: Connecting to XXX.XXX.XXX.X:21...
14:03:52 Status: Connection established, waiting for welcome message...
14:03:52 Response: 220---------- Welcome to Pure-FTPd [privsep] [TLS] ----------
14:03:52 Response: 220-You are user number 5 of 50 allowed.
14:03:52 Response: 220-Local time is now 14:03. Server port: 21.
14:03:52 Response: 220-This is a private system - No anonymous login
14:03:52 Response: 220-IPv6 connections are also welcome on this server.
14:03:52 Response: 220 You will be disconnected after 15 minutes of inactivity.
14:03:52 Command: AUTH TLS
14:04:30 Error: Could not connect to server
Hi,
I'm a new user of FileZilla. I'm not familiar with how the systems work.
I tried to connect with my server in Cpanel but it kept failing.
I've tried a few solutions from Google but it still not connecting.
Can someone suggest me something that really gonna solve this issue?
Thank you.

[Tim Kosse]

There is a faulty firewall or NAT router actively sabotaging the connection.