Xfinity/Comcast - CAX80 - Wifi speed went from 400 to 40 after newest firmware (help!)

[econgolf]

Ever since the new firmware V2.1.3.5 upgrade (which I've confirmed is what my router is currently running), my wifi speed has dropped from ~400MBPS to ~40 to ~60MBPS.  I've hard wired my computer to my modem and confirmed Xfinity is pushing around 700 MBPS into my modem (that's my wired speed); however, the wifi is only pushing out 40 to 60, at best.  I've been bounced back and forth multiple times now between Xfinity and Netgear phone support with each company blaming the other.  The Netgear website says I should be on version RG: V2.1.2.6 for Comcast, but nobody there can seem to figure out how to push it to me (they tried having me download the V2.1.3.5, which I already have).

I can't imagine I'm the only one with this issue?  Is there something I'm supposed to be doing or, which of the 2 companies actually has the fix?

Thanks!

[FURRYe38]

Has a factory reset and setup from scratch been performed since last FW update?

What wifi devices are you using?

What wifi freqency are the devices connecting too? 

Is Smart Connect enabled? 

What channels are you using? Auto? Try Auto and 48 on 5Ghz. Or try setting manual channel 1, 6 or 11 on 2.4Ghz and 40 to 48 channel on 5Ghz.
Any Wifi Neighbors near by? If so, how many?
https://kb.netgear.com/19668/Link-Rate-and-Transfer-Speed

Possible issues with 5Ghz are being noticed:

https://community.netgear.com/t5/Cable-Modems-Routers/CAX80-can-t-upload-5GHZ/m-p/2158905/highlight/...

[econgolf]

Thanks.  To answer your questions, below:

Yes, I did a hard reset while on the support line with Netgear.  We also tried changing the channels.  None of that worked unfortunately, and  their "answer" was that I'm on the wrong firmware when compared to their list of firmwares by ISP provider (it says Xfinity CAX80 should be on RG: V2.1.2.6.).  

Same issue whether I'm uisng 2.4 or 5 (in that it's noticably slower than it should be/was).

Devices - Dell laptop - speed test at 45.7mpbs

                Gaming desktop at same range

               Using the Nighthawk app as admin with my iphone, it shows speeds of ~330 to ~380mpbs

There is typically 0 to 3 other wifi networks "in range" at any point in time.

[econgolf]

Just checking to see if you have any thoughts based on my answers?  Thank you, Eric

What's strange is, if I do a speed test through an internet browswer, I should 30-80mbps.  However, using the Nighthawk app it shows >300mbps consistently.  The 30mpbs is the "actual" speed though, as I'm consistently losing/dropping facetimes, TEAMs video calls, etc.

[FURRYe38]

Ok so please understand. NH app only gives notification of the router side FW update only. Modem side FW comes from ISPs and they only push that when and if there testing completes. Modem side FW IS not user updateable. The router side FW is user updateable. 

Users are encouraged to update the CAX using a PC or laptop and manually download FW. Users can ignore the NH app if they want to. 

Though we've seen some issues on the 5Ghz side of this FW:

https://community.netgear.com/t5/Cable-Modems-Routers/CAX80-can-t-upload-5GHZ/m-p/2158905/highlight/...

You might try using v.4 of the CAX80 router side FW and see if this helps any.

Users are encouraged to contact NG support and let them know what your seeing. I believe this is a NG issue and not a ISP issue. My 2 cents. 

Im getting good speed with my CAX80 on recent FW however mines now back in modem only mode until NG fixes the wifi issues:

[davidbod]

FWIW, I got a CAX80 to replace my NG C7000 cable modem. Xfinity set it up and said everything was working on their end. They did some update to the WiFi part of the router even though I told them not to do it? I then tried with the NG app to connect to it to set it up on my side of the network, no go. Could not connect to WiFi even though it is scanning the label to get the name and password. Tried to connect manually with my iMac direct wired, no go, tried to connect WiFi with an iPhone and an iPad sitting 3 ft from it, no go. Basically it was bricked.

Sent the router back and have another one coming. This time I'm going to set my side up first and test things within my network before connecting it to the Xfinity side. At least that way I will know if it works before Xfinity touches it.

[FURRYe38]

Be sure to set up the CAX using a wired PC and web broswser. 

Also you'll have to connect the CAX80 to the coax line after you get it. The CAX80 will auto reboot continuously if it's not connected to a coax signal line. You should be able to setup the CAX prior to contacting the ISP for final activation on there network.