lftp returns "Data connections must be encrypted" for tls1.2

Issue

Tried to check using lftp, tlsv1.2 gives "ls: Access failed: 522 Data connections must be encrypted."

Red Hat Enterprise Linux 7

A Red Hat subscription provides unlimited access to our knowledgebase, tools, and much more.

Here are the common uses of Markdown.

Code blocks

~~~
Code surrounded in tildes is easier to read
~~~

Links/URLs

[Red Hat Customer Portal](https://access.redhat.com)