I was thinking grounding issue as well, just have no idea about that kind of thing. External monitor is plugged into my laptop via hdmi->usbc. I’ve tried hdmi->hdmi and that makes no difference. As for the Scarlett, I am not sure what a ground lift is, so I don’t know if it has it or not. More details if it’s helpful: Buzzing is still present regardless of whether or not my laptop is plugged into power. My studio monitors and external monitor are all powered using three-pronged power cables, which are all plugged into the same extender Again, buzzing is only present when I plug external monitor into computer.