I've encountered something incredibly odd in my home lab. My Hyper-V VM's have 10G, JumboFrames. Accessing each other, file shares, etc are super fast.

Accessing the internet, however, is slow... but ONLY on downloads. I have 300Mb down, 15Mb up and my vm's download at ~3Mb but

can upload at my max upload rate, no problem.

I can validate these slow speeds no matter where I go or what I do.

Now for the insanity.

If I install winpcap OR npcap everything is fixed.

I should mention I install them on the VM's themselves. The hosts are running Server 2019. I've been having this issue since upgrading to server 2019.

WTF!?