Internet speed inconsistency

[Davidc94]

I'm pulling out my hair trying to figure this one out...

So for some info, i just got spectrum 400 Mbps. I've tested every computer and each one is getting that speed. The only one that isn't is mine. My network is as this, Spectrum's router & modem in one corner of the house, with my Asus router being at the other end of the house, connected by a 150ft cat6 ethernet cable. Now I've tested my laptop, and computer to that cable itself, and my laptop is the one getting 400 Mbps, while my computer is getting 130 Mbps. When the cable is plugged into the Asus router, same thing happens (laptop 400, computer 130). My girlfriends computer is the exact same, besides graphics card, as mine and hers gets 400 Mbps. Am i missing something here? Any idea what this could be?

Sorry if i did anything wrong, 1st time poster here. Many thanks.
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Resolution:
OK, so i fixed it. turns out it was a windows auto-tuning setting actually being disabled. I enabled it and bam, worked. Heres the fix i found, and the specific part is under 3. Disable window auto-tuning: https://www.drivethelife.com/windows-10/fix-slow-internet-after-windows-10-anniversary-update.html

Edited February 12, 2020 by Davidc94
Fix

[TheBean]

what motherboard model is the desktop? do you know the exact model number?

[Davidc94]

Asrock steel legend x570 pro wifi AX. https://www.newegg.com/asrock-x570-steel-legend-wifi-ax/p/N82E16813157894?Item=N82E16813157894 If it helps.

[Davidc94]

More weirdness, a Linux VM i have on the machine in question is getting 400 Mbps but a windows VM is getting 130.

Edited February 12, 2020 by Davidc94
added more info.

[Davidc94]

OK, so i fixed it. turns out it was a windows auto-tuning setting actually being disabled. I enabled it and bam, worked. Heres the fix i found, and the specific part is under 3. Disable window auto-tuning: https://www.drivethelife.com/windows-10/fix-slow-internet-after-windows-10-anniversary-update.html