G36 WiFi 5Ghz Channel Speed Slower than 2.4GHz

  • 15 March 2024
  • 4 replies

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I’d welcome any insight as to what may cause the 5GHz WiFi signal on the G36 to regularly provide slower (19, 27, 35 40, 65mbps, etc.) network speed than the 2.4GHz (72mbps). 2 Coax cable connected devices meet network speed service levels (Network is WOW, Service Level is 300/20.) Only two devices connected to 5GHz channel (1 Android phone, 1 Tp-Link Mesh WiFi Extender.) Other factors for consideration:

  1. Both frequencies are using non-congested channels in my area (they are the only signal on their respective channels according to the WiFi Spectrum analyzer.)
  2. Bandwidth selection set to Manual: 2.4Ghz is 20/40; 5GHz is20/40/80
  3. Default settings for MU-MIMO enabled; DFS disabled
  4. Distance from the modem/router does not change these results (10 inches up to 50 feet.)
  5. Rebooting the modem/router does not change these results.

I’m unsure of any other potential signal interference to consider. I’m unsure if this issue is a product Warranty Issue. I did achieve 433mbps speeds when I first installed the G36, but that was about 1 month ago. (Could a Factory Reset vs modem reboot correct some hidden signal restriction or interference?) 

In any event thank you in advance for your time and consideration regarding this matter.

Larry G 


Best answer by SURFboard Moderator 31 March 2024, 00:42

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Userlevel 5
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Basically,  slow speed, intermittent connection or no internet access occurs usually out of cable signal level, out of acceptable range and it will be resolved after the power level are adjusted by the service provider. So for this we need to check the cable signal level to confirm what causing this issue to proceed further.

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Thank you so much for your insight and recommendation. I’m glad to hear this is not an equipment Warranty problem. I know from past experience that WiFi (and other) signaling issues can have many points of failure and without technical knowledge or the right equipment to analyze frequencies solutions are hard to achieve. 

Since it seems you know something about this type technical environment I have one other question before attempting to engage with the Cable Provider. Do you know or can you explain why the problem I’m having with the 5GHz Channel does not also exist (or is not noticeable) on the 2.4Ghz Channel or via the Coax cable direct connects? 

These two other channels currently have no drop off that I’ve noticed thus far. (Maybe its just a matter of time before a similar failure does occur.)

In any event, thank you again for your time and pointing me in the right direction to attempt to fix this issue. My next step will be with the cable provider and hopefully get someone that understands cable signal levels and the options to find a solution.


Larry G





Userlevel 5
Badge +41


It sounds like you're dealing with some slow Wi-Fi speed issues on both of the networks which is 2.4Ghz and 5Ghz (preferably more) 

The trouble shooting steps that you had mentioned are a good starting to check on the least congested Wi-Fi channels.

Let's try doing a Factory Reset and also try on this following step after logging on the web manager page ( 

Please go to gateway select troubleshooting and click on restart/restore and then select restart Wi-Fi and router.

Also check the Firmware version by going to Software option on the gateway 

If none of these steps resolve the issue, reaching out to would be a good next step.

They may be able to provide further assistance or recommend additional troubleshooting steps specific to your router 

Also consider the below mentioned points:

  • Check if the co-axial cable is proper and no crack or loose connection!
  • Not to place any electromagnetic device near the modem 
  • Ensure the modem is kept on an open environment. 


Note: Do check on the Speed plan that you are having with your (Internet Service Provider) and the Firmware Version





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Thank you for your guidance. Having completed most the recommended steps during the weekend of March 29-30 the G36 continued to fail. ARRIS tech support is/was outstanding, but the equipment continued to not perform correctly. My solution was to return the ARRIS G36 and exchange it for a comparable Netgear product. Out of the box the Netgear performed as specified and continues to exceed my expectations for range and speed. End of story. End of ARRIS G36.