Trackpad interrupts causing audio buffer underruns through speakers ONLY

Preliminary details:
OS: Windows 10 build 19045
Laptop: Framework 11th gen, DIY
CPU: i7 1165G7
RAM: 16 GB 3200 MHz

Recently I noticed an issue where when music was playing (usually through Spotify) and I try to do anything else, the audio would stutter and crackle. It sounded suspiciusly like buffer underruns so I downloaded LatencyMon and, lo and behold, any time I touch the trackpad the interrupt to process latency spikes to about 500 us. If I dare try to move the cursor while something else is happening in the background – opening a Chrome tab, running something in MATLAB – the latency jumps to about 8000 us. This is all from a baseline of ~140 us.

Here’s the fun part: this only happens when using the onboard audio. Playing through an audio interface? No problem! The onboard speakers however struggle to run. This might be because the interface is using ASIO, but I can’t be sure without running more tests… and I’m on vacation for the next month so I don’t have access to any of my gear.

Reinstalling drivers, updating windows, etc. has had no effect.

So, to summarise:
Touching the trackpad causes (significant) latency spikes which lead to buffer underruns when using onboard audio. Problem does not occur with a USB audio interface.