I tried using another USB-C cable with the standard power adapter and suddently the thing stutters really badly when plugged in. I’m not too sure if those things are related or if this is some other bug. According to nvtop, the dedicated GPU’s power usage goes from averaging around 30 W (unplugged, performance mode) to fluctuating wildly between 5 and 38 W (plugged in, any power mode).
edit: Charging it with my Android phone does not produce the stuttering
Edit: Resolved by getting a better cable rated for 240W
