AC2350 is not supported by Arris. Arris supports only the retail products that are available on surfboard.com but not the ISP lease products.

Do you have any Arris modem?

Hello, thanks for the response. It’s the SURFboard SBG8300 DOCSIS 3.1 Wireless Cable Modem with AC2350 WIFI which is on surfboard.com

Here is a link to it: https://shop.surfboard.com/surfboard-sbg8300-docsis-3-1-wireless-cable-modem-with-ac2350-wifi/?bvstate=pg:2/ct:r 

Since you are experiencing with intermittent internet connection on 2.4Ghz, I suggest you to change the Wi-Fi channels and monitor it for next 24hours of time.

To change the Wi-Fi channels, find the link given below:

http://arris.force.com/consumers/articles/General_FAQs/SBG8300-Changing-the-Wi-Fi-Channel

If you are unable to connect the devices with 2.4Ghz, I suggest you to change the security mode by following the steps given below:

>Launch the web browser and enter IP address 192.168.0.1 on the address bar.

>Login the Arris surfboard portal with credentials.

>Select Gateway>Summary>Connection>Wi-Fi>Network and select edit for 2.4ghz.

>Change the security mode as WPAWPA2-PSK(TKIP/AES).