TUF AX6000 slower ethernet speed than wifi (both below router speed test)

[Axenos]

Hi,

Recently got an Asus TUF AX6000 and i'm getting 925.71Mbps dl and 647.40Mbps upl speed on the router speed test.
I've got my PC connected via ethernet on the 2.5GB port and the link between the router and pc is shown by Win10 is at 2.5GB. Running speed test on the PC i get 700Mbps dl and 640Mbps up. Tried a different ethernet port on the PC which is 1GB and got the same speeds.
I've also tried running a speed test on my iPhone connected on wifi and got around 800Mbps dl and 640Mbps up which is higher than the wired connection.
Tried changing the cable, a factory reset on the router and disabled all that i could but without any improvements.

Has anyone had this issue? Any thoughts on what might be the cause?

[jzchen]

The first suspect is QoS got enabled/turned on.  As background I never turn it on, (intentionally), and somehow found it on one day (on a different model ASUS router).

The next suspect is Windows settings for the Ethernet driver.  Uninstalling then reinstalling the driver may help it auto configure properly...

[Axenos]

I’ve double checked and QoS is disabled. 
Also for the PC Ethernet I’ve tried 2 different Ethernet ports and the windows reset function. 
I’ll try the uninstall reinstall but I think the windows network reset does that also.

[Axenos]

Tried a driver reinstall and nothing changed, any other thoughts?

[jzchen]

Is it possible to connect the PC directly to the modem/ONT and speed test run, (to completely rule it out)?

[Axenos]

Tried a direct connection and it’s limited to 700mb so it seems that is something from the PC. Might have to do a win reinstall as it’s quite old and the driver reinstall didn’t do anything.