Windows 10: Windows 11 throttling ethernet port to 100mbps

Why is windows 11 throttling my ethernet connection down to 100mbps? I have a 2gbps fiber optic eero router and a 2.5gbps ethernet card which initially showed 2.5gbps under the network status. I can change from auto negotiation to 2.5gbps but that seems counter intuitive since auto negotiation should not be resetting my connection rate to something less than what is actually available from my router.

:)

 

Ethernet suddenly running at 100Mbps instead of 1000Mbps

Hi,

So, a few weeks ago I had some problems with getting 1000Mbps running (it ran at 100Mbps) on the motherboards ethernet port. It ended in me buying a PCI-E express card, and the connection started running at 1000Mbps.

The PCI-e card is of model TP-Link TG-3468.
The router is of model ASUS RT-AX82U.
My Windows Version is "Version 20H2 (OS Build 19042.746)"

Fast forward to yesterday, when I (unrelatedly) installed a switch between the router and a couple of other connected devices. I noticed that my desktop computer started running at 100Mbps again, and I can't get it to run at 1000Mbps. I'm not sure that it's related to me installing the switch (it shouldn't be).

Some things I've tried/other info:

• The desktop computer not getting gigabit speed is not connected to the switch - it's connected directly to the router.
• I tried connecting a Raspberry Pi 4 with the same cable that the desktop computer is using, and it gets 1000Mbps speed. So - the cable doesn't seem to be the problem.
• I tried switching the PCI-E slot that the gigabit card is installed into, and it doesn't make a difference-.
• I tried installing the latest drivers (both from TP-Link:s website, and Windows Update). No difference.
• I tried forcing gigabit speed in the settings of the adapter, but it still connects with 100Mbps.
• I tried connecting the desktop computer with a brand new cat 6 cable, and it still connects at 100Mbps.
• I think some Windows Updates was installed a few days ago. Don't know if it could be related.

Does anyone have any suggestions in getting my connection to run at 1000Mbps again?

 

Speed stuck at 100Mbps on 1Gb Fibre

PC is custom built

Speed and Duplex were set to Auto Negotiate but Ethernet Speed was stuck at 100Mbps which is why I have forced it to 1Gbps, but the Ethernet Speed remains the same 100Mbps

Please read the original post as stated the PC is connected directly to the Router via Cat8 Cable.

Power Managment is not the issue everything related to saving power is Disabled

I have even restarted my PC in Safe Mode with Networking and as stated before The Speed and Duplex remains set to 1Gbps but the Ethernet Speed is still at 100Mbps

This means it is not an external program throttling my speeds

 

Ethernet port not blinking...

possibly your ethernet port has died...

Unless if you format/reinstall windows , and see if that way... but overall, physically take a look at the motherboard in the computer, and see if any capacitor's top's have blown open or even have a bump on them (the tops of the capacitors should be flat) . If any indication that happens, then your mobo is eventually gonna die.

Other than that, u went through all other steps that are very known..

**My Friends system not to long ago has the exact same issue, and there were caps blown, but only the ethernet didnt work