Netgear CAX30 Modem Firmware Update Causing Internet Connectivity Issues

Is this an issue with the router or the modem?  What exactly does doing a factory reset do to fix the problem?

Is this an issue with the router or the modem? ...

The poster has worded their message in an unfortunate way, referring to the CAX30 as a 'modem' in their Subject line and as a 'router' in the message body. The device is a combination modem+router gateway: see https://www.xfinity.com/support/devices and/or https://www.netgear.com/support/product/cax30.aspx.

I do not know the answer to your second question. A prominent banner on https://www.netgear.com/support/ directs owners to https://kb.netgear.com/000065543/My-Nighthawk-CAX30-Cable-Modem-Router-is-not-connecting-to-the-Internet-what-do-I-do, but neither page explains how the "fix" works, and AFAIK neither has Comcast.

Please be aware that there are 2 kinds of responses in this Forum: Replies and Comments. When you Comment on a post by scrolling down to "Comment on this post here...", I am notified of your response. But if you select Reply, I am NOT notified and may not be aware of your response.

Even after doing the factory reset on my new CAX30, I saw the following issues in the past day: 1) Wifi connections peculiarly do not get internet for few devices, even with Wifi symbol ON and connected 2) Wifi connections drops time to time 3) Wired LAN connections are more stable, and gets alienated with no internet very rarely. I think my new CAX 30 cable modem router is a brick now. I am using the same SSID as before with WPA2/WPA3 encryption. I don't like to go around house and reset everything!

Here are my versions from admin console after factory reset:

Firmware Version V2.1.3.10

Cable Firmware Version V1.04.10

I got this new cable router modem 10 days back from costco,  after xfinity and netgear possbily screwed C7000v2 cable modem router with an update too. Had similar symptoms! huh! I did not try a factory reset on that though. Possibly the same bug spread across all firmware updates.

The fix cax30 instructions did not work for me.

Should I not change the default ssid after factory reset?

Should I connect all devices to 2.4Ghz. It seems more stable than 5Ghz?

Thanks for the reply, @user_bfb8dc.  These firmware versions match what are on my Modem/Router.  It seems there are multiple threads about issues with this Modem/Router.  Netgear shows the current firmware version as 1.4.11.2.

https://www.netgear.com/support/product/cax30.aspx#download

This is a new Modem/Router for me.  I've had it less than a month.  Prior to that, I had a C6900 that was providing less than 10% of the speed it should have been providing.  I was told by one tech, the C6900 had failed.  So, I replaced it with a CAX30.  I had a second tech out who told me the line from the tap box to my house was old and needed to be replaced.  So, he replaced it.

I have Comcast Gigabit Plus service and The best I can get is about 700Mbps.  This morning, I'm getting 372Mbps.

I am having the same problems with my CAX30. We had a tech from Xfinity come out yesterday and were able to get full internet service through both hard wired and wifi connections. Then last night the wifi started working intermittently and this morning I have zero internet connection through wifi. The hard wired connections are still working. Is there a way to prevent the modem/router from updating itself? Is NETGEAR doing anything to solve this problem or are we just stuck buying a new device?!?

Time to try on Motorola or Asus, or go for fiber. I got really [Edited: Language"] on important remote office meetings twice already with netgear wired LAN ghosting me!

Netgear cable modem routers are great until like the last 4 months since Nov 2022, possibly [Edited: Language"] updates. If netgear can share how a factory reset magically bring things back up to normal, I can still hang on few weeks. I am assuming the device would automatically update again even after the reset and even if xfinity does not update its recent cable version update after the incident. 

i will wait one more week in this mess for some coordinated solution from xfinity and netgear. Else, I am gonna try other vendors. 

Can netgear tell us for a recent bought CAX30, after factory reset and ensuring that the traffic meter is off, what should be the router Firmware Version and Cable Firmware Version we should look for?

I'm sending mine back for a refund.  My C6900 that was reported to have failed, is working like a charm.

Best of luck to you all

Factory reset worked initially for me...but then seems to stop working. And when I set to my "custom" ssid - it simply doesn't work (at least 5ghz wireless). Is there a fix coming? Or do I have to bite the bullet and buy new hardware?

I am having the same issue with my 5Ghz Network as well. My device shows as connected to it but no internet. 2.4Ghz works without any issues. I got on call with a Netgear Support, he downgraded my firmware , so now earlier before this issue started I used to get 500-600 Mbps on my wifi, it has been reduced to 150 Mbps. 
Netgear Engineer is saying speed will increase after 24-48 hours after the firmware was changed.

This issue is a MESS !!

At least AT&T fiber is now available to me.

Did I mention, I scheduled an a service appointment - got a text and email confirmation, but nobody actually showed up. When I asked...the appointment was cancelled, nobody told me and they couldn't tell me why. Not the service I expect. I tried... 

The factory reset does not work for me.  I had to go to a previous firmware to be able to just get it talking, but now my wifi speeds are almost zero.  Hardwired works fine.

This is how I got my CAX30S working again :

• 1. Remove COAX and all other lan cables from your modem. Keep the power chord plugged in.
  2. Press the reset button for 45 seconds. It will hard reset the router. 
  3. Release the button and wait for 3-5 minutes for modem to settle in.
  4. Once the modem lights are solid, attach the coax and all other cables.
  5. Wait for 5-10 minutes for modem to connect to internet and refresh.
  6. Check the wifi name, they should be reset to factory names.  Make sure that you don't see your old wifi names in phone/laptop. This gaurantees hard reset was successful.
  7. Cofnigure your wifi settings like name, password etc and connect to the network.
  8. Test your speed over Wifi (2.4 Ghx and 5 Ghz) and wired connections.
  10. Your speed be what you would have expected
  
  Let me know if this worked for you guys

What revision are you at in the router