CAX80 Stuck at 100mbps when using Multigig Port for Ethernet

[Talon2020]

Just started yesterday, my CAX80 multigig port no longer works beyond 100mbps. Tried with 2 different NIC on my motherboard, both produce same result. Also switched my ethernet cable and same results. Did a few reboots, driver installs, and nothing seems to be working. I also did a factory reset on the modem/router twice and same results. I also tried to manually edit the speed in the device properties and that also did not work, and would either not recognize the internet connection or would still revert to 100mbps. Tested my phones and laptops all work great over WiFi with correct speeds.

Then I tried my LAN1 port and discovered it works but maxes at 1000mbps which is what it's rated for. Using the Multigig port I was getting between 1100-1300mbps down on my Xfinity connection. Does this sound like a dead port or a damaged port? Is there anything else I can try to restore my multigig port to full working status? 

[FURRYe38]

What is the mfr and model# of these NIC adapters your using? 

Something i have seen with mine though I have a Orbi RBR850 connected to mine making a 2.4Gb connection.

[Talon2020]

Network Card: Aquantia AQtion AQC107 10Gbit Network Adapter

Network Card: Intel I225-V Ethernet Controller

Both exhibit exactly the same issue of max 100mbps connections and both were working 100% until just a few days ago. It started out of nowhere, no Windows or drivers updates were applied or changed. I verified the driver version and even tried to clean reinstall the driver. Tried different cables, and issue persists. 

Both network adapters work 100% at 1000mbps link when switching to the LAN1 port. However that isn't a "fix" as the Multi-gig port should work as intended like it did before. 

Does it sound like I need to start an RMA with Netgear? 

[FURRYe38]

I would yes. Keep us posted on how it goes. 

[Talon2020]

Did the RMA with Netgear over the phone. Took about 20 minutes of speaking to their intial adviser and letting them know what I had done on my end to trouble shoot the modem/router and after a brief hold so they could confirm with their higher level support they issued me an RMA.

I took the advanced RMA option which I was thankful they had since I need the modem/router for work and didn't want to drag out an old device and go through the process of activating and reseting my home network. Took a couple days and got my new unit. After some initial setup issues with Xfinity not being able to activate the modem properly it finally worked (took 4 activation signals from Xfinity). I've been using it for about a week now and everything has been great. Multigig Port working as it should. I really hope this unit lasts a lot longer than the first unit and hopefully I just got a lemon. 

[FURRYe38]

Thanks for letting us know. Hope it works well too. Please mark your thread and solved so others will know.

Enjoy.