svchost.exe high cpu usage while using higher bandwidth

[Saltatio15]

I recently set up a new windows 11 installation on my main pc. Everything works great, I have only one problem. Everytime I use more than ~25Mbit/sec of download bandwidth, my svchost.exe spikes in its cpu usage to more or less 100%, which slows everything to a crawl and also can't be good for the processor...

It happens if I watch a youtube video in 4k (with firefox, brave and opera) (in 1440p everything is fine). It also happens with downloads from i.e. steam. If I cap the download speed with netlimiter (netlimiter ist not the culprit, I installed it recently to investigate the problem) to 20 Mbit/sec, nothing happens. But once I increase the cap to 30, svchost spikes. Sometime it is enough to pause the video/download, sometimes I have to close the tab/steam completely to get it back to normal.

I tried a lot of different things I found on the internet, but most are older and far less specific problems with svchost. A clean re-install is my last hope, but I wanted to ask here first if somebody has any idea or knows a similiar problem.

 

specs:

Win11 Pro build 22621.1105

ASRock X370 Pro4

AMD Ryzen7 2700X

32GB RAM

Nvidia 2070 Super