Audio stuttering in video calls and during high disk IO

I have a Librem13v4 running NixOS. The issue I’m having is that during video calls (Google Meet), the audio stuttering is so bad that it’s basically impossible to hear what the other party is saying. The other party also reports an echo coming from my end. This happens on both Chrome and Firefox. However, other uses of audio and video (for example, Netflix and youtube) don’t have any audio issues.

As I was trying to pinpoint the issue, I found that I could reproduce the issue by trying to play an mp3 file in Firefox or Chrome and running a high disk IO load (by simultaneously running the command stress -d 8.

Any idea what could be causing this?