Start easy. Close background apps one by one to see if one of them is the culprit.
As I said above, use resource monitor in Windows to see which process is using network at the time your stutters happen. This can get a little tricky though, so I would just get a free version of Glasswire. It has a graph of network usage. You can click on a spot in the graph corresponding to when your stutters happen and it will show which processes were using the network and where they communicating to. There are other tools that can do the same thing as well or better, but that is the one I used to find out dasHost.exe was creating stutters.
A more powerful tool is sysmon (Sysmon - Sysinternals | Microsoft Learn), but it is admittedly more difficult to set up and use.