Hi,

I have 3 Deco X55 configured as a wifi router mode. The 3 decos are all connected to one another via wired Ethernet. My ISP is a fiber connection with 600Mbs download/upload.

I have several Linux and Windows PCs connected to the Deco(s), some via wired and some via wireless.

On all my linux PCs, when I run the speedtest.net, I get a solid 600Mbs down and up through the network.

However, on the Windows PCs (some Win 10 and some Win 11), I am getting 1.5 to 2 Mbs download via the speedtest.net, but a sold 600Mbs upload on the same PC.

2 tests that I've run, both with wired connections directly to the Main Deco:

1. A Windows 11 laptop connected via ethernet cable directly to the Main Deco, I did a speed test and got 2 Mbs down / 600 Mbs up. 
I then connected directly to the ISP fiber and got 600 Mbs down/up.

2. A Windows 10 PC directly wired via ethernet to the Main Deco, same story: 2Mbs down / 600 Mbs up. 

Then I rebooted the same PC into Linux Mint with no hardware changes. I get 600 Mbs down / up.

I do not have QoS turned on.

I have updated windows drivers on the Windows 10 PC and made sure it was up to date with updates. The NIC is an Intel I217-LM (rev 04).

I'm at a complete loss on how to debug/troubleshoot this further or why the same PC works fine running Linux but has such slow download speeds in Windows (and this is the same for ALL the PCs running Windows).

The above tests seem to point to an issue with the Deco router since connecting directly to the fiber network and the problem goes away.

Can you please help with this issue?

Thanks.