Some distributions of linux by default will enable IPv6 "Privacy Extensions" (defined in RFC 4941), which is not supported on Binary Lane.
When this is enabled instead of using the auto-configured address that can be seen in mPanel, Linux will create its own address essentially at random. This random address will not work, which can result in sporadic or permanent problems when using IPv6.
You can correct this issue by disabling the privacy extensions. To do so login with SSH and execute the following as root:
cat >> /etc/sysctl.conf <<EOT
net.ipv6.conf.all.use_tempaddr=0
net.ipv6.conf.default.use_tempaddr=0
EOT
sysctl -p
Once this is executed, with a few seconds the operating system will switch to the standard auto-configured address shown in mPanel.