T-Mobile 5G Home Internet Gateway slow ethernet but fast WiFi

 I have the same problem no one could find the error and fix it? 

I was seeing < 100 on my existing ethernet LAN while getting 350-400+ on the native gateway wifi.

I connected a pc directly to the TM gateway ethernet (bypassing my existing LAN) and saw fast speeds of 300+.

This pointed to an issue with the TM gateway negotiating with my existing LAN. My LAN is driven by my own wifi router.

I had changed my router to use a non-192 prefix IP address for the LAN. So I reverted this back to 192. And now my ethernet is much faster but not as fast as native. Getting 200-250, which is a lot better than < 100.

Doing a lot of testing shows the TM-gateway is throttling / load balancing between its wifi and ethernet ports. My hunch is the amount of devices on my LAN is putting some nominal load so I'm not seeing 300+ on a single device there.

Also my LAN also hosts some access points; these needed to be restarted to hit the 200-250 speeds (they were still stuck on < 75)

I dumped T-Mobile internet and go back to Xfinity.  T-Mobile has not resolved the issue.

1-slow LAN ethernet speed (70-90mbps)

2-VPN kept dropping 

3-The internet disconnected multiple times/day

4-T-Mobile streaming low quality or low resolution (max 720p).  if you stream from mobil device then you won't notice this.  Otherwise, from 1080p-4K TV,  The pictures is very very blurry.

I suggest that you guys can dump T-Mobile internet (they are not ready yet as ISP)

Same issue.

400Mbit on wifi, 2-3Mbit on ethernet. Something broken.

Same issue & plus

1- The current modem has been dropping connections so many times during the day.  We have a hard time while connecting/remote to my work place through VPN.

2- The ethernet speed is very slow (60-70mbps)  but wifi is more than 200mbps.

I read these issue from the TMobile forum and they suggested the modem model: G4AR. 

3- Watching youtube on either wifi and ethernet is extremely blurry.  I think Tmobile is limiting the youtube speed on their end.

We called TMobile about the issue and the tech support ask us to pay $55 for the internet service which we have to pay $5 more for our current plans is $50. 

Seems like TMobile is trying to charge the customer more money to get better internet.

The customer service/tech support did not resolved our issue. 

Same issues and tech support acted like they've never hear the issue before.  Didn't offer any assistance and said any hardware I connect via an ethernet port they're not responsible for the speeds. 

I hane the same issue.   

Slow LAN speed (<100mbps).  Wifi is fast (>400mbps)

Reset and reboot did not fix the issue.

I figured it out, guess reading here put a bias in me that it was somehow the gateway’s issue if WiFi’s fast but Ethernet’s slow… it was my fault lol, if you’re having the same issues perform the following steps before bugging tech support --

1. Uso https://www.speedtest.net/ and set the same server for testing, do NOT use Google’s M-Lab that comes up in a blurb when you search speed test (it’s highly inconsistent)
    
2. Run speed test via another browser to see if you get the same results, if you’re getting discrepancies it may be VPN / secure DNS, etc. Make sure your VPN software isn’t running, if on Windows check Internet Options → Connections and make sure there’s no VPNs that’s slowing you down
    
3. Check another device and a third device via Ethernet, if you’re getting discrepancies it’s not the gateway’s problem 
    
4. Uninstall your NIC driver and update to the latest, for me it was https://www.realtek.com/en/component/zoo/category/network-interface-controllers-10-100-1000m-gigabit-ethernet-pci-express-software
    
5. Perform a “Network Reset” under System Settings, just type in your search bar
    
6. Worst case if you have a PC that’s still just not performing, buy a new $13 NIC card on Amazon

Now I’m getting 200-400 Mbps on all devices with my old router, a bit inconsistent but beats 4G speeds by a long shot! 

Just got my unit today, same issue (showing firmware ver. 1.00.16)

~200 / 45 Mbps over WiFi direct to gate way

~6 / 5 Mbps direct via any of the two ethernet ports (removed my router from the equation, tried hard resets, Network reset, nada)

For those that got a gateway replacement did that fix the issue?

I use to get over 300 mbs on the wired or wi fi, now I'm lucky to get 100 mbs. Hard wired should be faster I would think?