I am having the same issue. Using Xfinity/ Comcast in Colorado. I have tried resetting the modem several times as well as enabling/ disabling the 5ghz networks on the admin site

Hello @prayag, @knausewg 

Sorry to hear about your 5 GHz Wi-Fi cutting out on your G34.  I’ll be happy to look into it.  How long did the 5 GHz Wi-Fi worked for before the issue started?   

Please share the G34 software version, 5 GHz Security Mode, and screenshot of the Wi-Fi 5 GHz Radio settings.  You can find those information on the following screens.

Software version: https://192.168.0.1/software.php
5 GHz Security mode: https://192.168.0.1/wireless_network_configuration_edit.php?id=2
5 GHz Radio: https://192.168.0.1/wireless_radio_configuration.php?id=2

Hello,

I am also having the same issue as @prayag and @knausewg, so I can provide some information as well.

My G34 was working fine for 3 months, and the 5GHz option just disappeared all of a sudden yesterday. My 2.4GHz is working fine.

Below are the information you requested. It’s default factory setting, so I presume others would have the same setting.

 

To @prayag  & @knausewg ,

Arris customer service was able to address this issue for me. I just followed the steps in the link below (provided by the Arris rep).

https://arris.my.salesforce-sites.com/consumers/articles/General_FAQs/G34-G36-Changing-the-Wi-Fi-Channel

Seems like the issue is that the modem may default into a 5GHz radio channel that is used by too many people in your area; therefore causing interference and making your 5GHz option disappear. If you run the scan per the instructions, and manually change it to a channel that is used least - it should make the 5GHz option appear.

It worked for me instantaneously. Just sharing the help I got. Hope this helps

This solution works for me! Thanks!