Question Ethernet Is Slower Than Wifi

[Carbo]

Laptop: Dell XPS13, model 9360;
Modem: Netgear CM1100
Router: TP Link AX50
ISP: Xfinity, Extreme Pro Tier, rated 900Mbps
My laptop is hard wired into the router, which sits about 4 feet above my desk. My service is usually trouble free, and my ethernet connection will usually clock in at about 925Mbps according to Speedtest.net. Wifi speeds are usually between 300-350Mbps throughout the house. In both setups uploads are a consistent 24Mbps.
For the past week or so my ethernet speed is running between 125-200Mbps, while Wifi remains at its usual speed. With my limited know how I have done the basics: powered off modem and router multiple times; swapped out the cable between the laptop and router, same results; plugged in a second laptop, same results. (If it matters the WiFi card is an Intel AX200.)
The connection between the router and laptop is with a USB-C to Ethernet adapter. Since I don’t have another to test, I don’t know if this is the issue.
As I said, with my limited know how I’m pretty much stumped. Suggestions? Appreciate the help!

 

[Tech Junky]

So, when you bypass the TPL and test direct with the CM what speeds do you see? If they're what you consider "normal" then the issue is the TPL.

If you move files between devices connected to the TPL wired then you should see the max speeds ~980mbps on a 1gbps port.

 

[Carbo]

I just ran the laptop directly through the modem. Same result, about 100Mbps.
Could it be a bad modem? Puchased about 2.5 years ago. Hate to think it's already a paperweight.

 

[Tech Junky]

Ehhh.... try a hard reset on it by holding the reset button down for 10 seconds and test again. Try another Ethernet cable just in case. Still doesn't perform then consider switching the modem. I use an MB8600 and haven't had any issues for 5+ years.

 

[In2Photos]

If you get 300 using WiFi from the router then the issue is not the modem. Sounds like your USB to Ethernet adapter. Try reinstalling the drivers for it. If that doesn't work get a replacement.

 

[lakedude]

Try flipping the USB-C cable the other way or just exercise the connection.

My Samsung Galaxy S8 started acting up after a few years of excellent service. It was the connection at the C port.

 

[mpo]

Laptop: Dell XPS13, model 9360;
Modem: Netgear CM1100
Router: TP Link AX50
ISP: Xfinity, Extreme Pro Tier, rated 900Mbps
My laptop is hard wired into the router, which sits about 4 feet above my desk. My service is usually trouble free, and my ethernet connection will usually clock in at about 925Mbps according to Speedtest.net. Wifi speeds are usually between 300-350Mbps throughout the house. In both setups uploads are a consistent 24Mbps.
For the past week or so my ethernet speed is running between 125-200Mbps, while Wifi remains at its usual speed. With my limited know how I have done the basics: powered off modem and router multiple times; swapped out the cable between the laptop and router, same results; plugged in a second laptop, same results. (If it matters the WiFi card is an Intel AX200.)
The connection between the router and laptop is with a USB-C to Ethernet adapter. Since I don’t have another to test, I don’t know if this is the issue.
As I said, with my limited know how I’m pretty much stumped. Suggestions? Appreciate the help!

I started having issues with an Anker USB-C hub a few weeks ago. The hub worked fine for over a year. Then, started getting an unstable internet connection during sustained downloads or video conferences. Internet would drop out two or three times per day. This was with a Dell Latitude 5520 laptop.

Ended up having to update Realtek USB GbE Family Controller under Device Manager. First tried the latest driver from the Dell site. Helped a little bit--the issue would show up every few days.

Downloading the latest driver straight from Realtek solved the issue.