Mobile devices randomly getting intermittent Wi-Fi connectivity.

[Dohness]

This morning I noticed my iPhone was still connected to my Wi-Fi network but was unable to get connectivity.

After some general basic troubleshooting including, forgetting the network and reconnecting the device, power cycling the device, the issue appeared to be resolved.

However, fast forward a few hours later and the issue reappeared intermittently, following the same troubleshooting steps as before seemed to resolve the issue again, but only for about 30 - 60 min before becoming a persistent issue.

As a result I have also attempted to power cycle the CAX80, verified firmware up to date. Also verified via the router admin that it can see the device connected via the 5Ghz, the IP and MAC match what the iPhone shows, no duplicate information present, and access is allowed.

After mentioning this situation, my wife also reported the same issue with her iPhone briefly yesterday.

All other devices seem to be unaffected and working as normal. We currently have 10 - 11 devices via Wi-Fi frequently and peak between 13 - 14 when everyone is present.

At this point I'm unsure how to troubleshoot this.

[FURRYe38]

What FW version is loaded? 

What channels are you using on 2.4 and 5Ghz? Try 1 and 40. 

Set 20/40Mhz Coexistence to 40Mhz only Under Advanced Tab/Advanced Settings/Wireless Settings

[Dohness]

"What FW version is loaded?"
 Modem is currently running V2.1.5.2.

"What channels are you using on 2.4 and 5Ghz?"

2.4 was running on 7 and 5 was on 36, I will update to 1 and 40 and see if there are any changes.

"Set 20/40Mhz Coexistence to 40Mhz only"
Just to make sure I'm understanding this correctly, in order to do this would I just need to untick the 20/40 Coexistence, as my advanced page does not appear to show a "40Mhz only" option.

[Dohness]

Update @FURRYe38 

I have changed the 2.4 and 5Ghz from Auto detect to specifically channels 1 and 40, also toggled the 20/40Mhz. After doing these changes the issue returned right away so I power cycled my iPhone as well as the CAX80, but still encountered the issue.

I enabled the 20/40Mhz again, and that seemed to resolve the issue for over an hour. However, as soon as I moved the iPhone from the room the CAX80 is physically located, the issue resurfaced.

Additionally, I discovered our iPad is also now encountering the same issue as the iPhones. All other connected devices remain unaffected.

[FURRYe38]

Have you tried disabling AX mode on both radios? 
Maybe try disabling Smart Connect? 

[Dohness]

Appreciate the response and suggestions, unfortunately the seems to still be persisting.

Additionally, it appears the speed issues I had mentioned in my previous post with my Xbox consoles has also returned. 

At this point this leads me to believe this issue is with the hardware or FW with the CAX80 itself. I'm going to attempt a factory reset of the modem and start over from square one, if all else fails at this point the device will be returned to the retailer.

[FURRYe38]

Be sure to try channel 1 and 40. 

Set 20/40Mhz coexistence to 40Mhz only. 
Enable WMM, Beamforming and MIMO as well. 

What Firmware version is currently loaded?
Please post a copy and paste of the modems connection status and event log page.
https://kb.netgear.com/30007/How-do-I-obtain-the-cable-connection-information-from-a-NETGEAR-cable-m...
https://kb.netgear.com/30008/How-do-I-view-or-clear-the-event-logs-on-my-NETGEAR-cable-modem-or-mode...

[Dohness]

After completing a reset of the modem and starting over fresh, I verified the firmware version and it remains V2.1.5.2, I also manually assigned the Wi-Fi to channels 1 and 40.

I was able to verify Beamforming and MIMO are both enabled. However, I'm not actually seeing an option for WMM / "QoS" in my advanced settings any where.

For the moment the issue appears to be resolved with the mobile devices under the new SSID.

Connection status:

Cable Diagnostic

Status:   Good

Internet Access: Green

Downstream Status: Green

Downstream Power Level: Green  Downstream SNR: Green

Upstream Status: Green

Upstream Power Level: Green

Event log since reset:

Thu Jan 12 13:20:54 2023	Critical (3)	SYNC Timing Synchronization failure - Loss of Sync;CM-MAC=34:98:b5:cf:dd:19;CMTS-MAC=00:7e:95:40:f9:61;CM-QOS=1.1;CM-VER=3.1;
Thu Jan 12 13:08:44 2023	Warning (5)	Dynamic Range Window violation
Thu Jan 12 13:08:44 2023	Warning (5)	RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=34:98:b5:cf:dd:19;CMTS-MAC=00:7e:95:40:f9:61;CM-QOS=1.1;CM-VER=3.1;
Thu Jan 12 13:08:44 2023	Warning (5)	Dynamic Range Window violation
Thu Jan 12 13:08:44 2023	Warning (5)	RNG-RSP CCAP Commanded Power in Excess of 6 dB Below the Value Corresponding to the Top of the DRW;CM-MAC=34:98:b5:cf:dd:19;CMTS-MAC=00:7e:95:40:f9:61;CM-QOS=1.1;CM-VER=3.1;
Thu Jan 12 13:08:40 2023	Notice (6)	DS profile assignment change. DS Chan ID: 32; Previous Profile: ; New Profile: 1 2.;CM-MAC=34:98:b5:cf:dd:19;CMTS-MAC=00:7e:95:40:f9:61;CM-QOS=1.1;CM-VER=3.1;
Thu Jan 12 13:08:32 2023	Notice (6)	TLV-11 - unrecognized OID;CM-MAC=34:98:b5:cf:dd:19;CMTS-MAC=00:7e:95:40:f9:61;CM-QOS=1.1;CM-VER=3.1;
Thu Jan 12 13:08:32 2023	Error (4)	Missing BP Configuration Setting TLV Type: 17.9;CM-MAC=34:98:b5:cf:dd:19;CMTS-MAC=00:7e:95:40:f9:61;CM-QOS=1.1;CM-VER=3.1;
Thu Jan 12 13:08:32 2023	Error (4)	Missing BP Configuration Setting TLV Type: 17.8;CM-MAC=34:98:b5:cf:dd:19;CMTS-MAC=00:7e:95:40:f9:61;CM-QOS=1.1;CM-VER=3.1;
Thu Jan 12 13:08:32 2023	Warning (5)	DHCP WARNING - Non-critical field invalid in response ;CM-MAC=34:98:b5:cf:dd:19;CMTS-MAC=00:7e:95:40:f9:61;CM-QOS=1.1;CM-VER=3.1;
Thu Jan 1 00:02:59 1970	Notice (6)	Honoring MDD; IP provisioning mode = IPv4
Thu Jan 1 00:02:53 1970	Critical (3)	No Ranging Response received - T3 time-out;CM-MAC=34:98:b5:cf:dd:19;CMTS-MAC=00:7e:95:40:f9:61;CM-QOS=1.1;CM-VER=3.1;
Thu Jan 1 00:02:39 1970	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=34:98:b5:cf:dd:19;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Thu Jan 1 00:01:26 1970	Warning (5)	Lost MDD Timeout;CM-MAC=34:98:b5:cf:dd:19;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;
Thu Jan 1 00:01:18 1970	Critical (3)	SYNC Timing Synchronization failure - Failed to acquire QAM/QPSK symbol timing;;CM-MAC=34:98:b5:cf:dd:19;CMTS-MAC=00:00:00:00:00:00;CM-QOS=1.1;CM-VER=3.1;

[FURRYe38]

I see some Criticals and Errors that the ISP should review and help resolve. 

Can you please port the bottom portion of the Cable Connections status page as well.