Internet speed slow/throttled on new PC in Windows 11

[zypther]

 

I recently built a new PC, but the internet speed over ethernet appears to be having trouble.

File downloads are very slow and often freeze, websites are often slow to load or load incompletely, and videos on sites like YouTube are low res and frequently buffer or stop loading.

Running a speed test returns download speeds that I would expect but upload speeds near or at 0.

Strangely, I don't notice problems with watching livestreamed video on Twitch or maintaining good connections in video games once I've loaded into a server (e.g. Valorant will tell me that I have high average ping or bad network connection upon joining a server but this notification will quickly disappear and I will have low ping and no noticeable lag when actually playing).

This problem only exists when I boot into Windows 11. When I boot into Linux using a bootable Ubuntu USB stick I have no issues whatsoever with internet connectivity/website or video loading/etc.

I've tried a number of things to fix this problem including a clean install of Windows 11, but unfortunately nothing has worked so far to fix the issue. Any help would be appreciated!

My specs are:

Windows 11
MSI MAG Z690 Tomahawk WiFi DDR4 (BIOS version 1.10)
Intel i7 12700K
2x16GB TridentZ RGB 3600 RAM
Samsung 980 Pro SSD (1TB) boot drive
EVGA SuperNOVA G6 (1000W 80+ gold)