Re: Zytel router suddenly unsecured - but only one one channel (5ghz)
Indeed, this is not normal behavior and both networks should be secured. Note that the firmware is programmed to restore all default information including the Wifi security if you perform a factory reset on the unit. This could be a solution to enable the default Wifi security and password . However, this will also set back to default any option you may have changed (eg. admin and wifi password, port-forwarding, parental control, etc.).
We sent you a private message, if you would like to send us your contact information, an agent can contact you to verify this issue in more detail. Alternately, do not hesitate to contact our technical support that will be able to help you: http://www.videotron.com/residential/contact-us.