Intermittent buzz with E30/L30 combo

Hello all, I’m having a slightly strange issue. Just today I’ve notice a small low volume buzzing sound. It’s very intermittent, usually 3-5 short one second buzzes followed buy minutes of silence before it happens again. It happens even if no sound is being played, and the number of buzzes, and length of time between the groups is inconsistent. I tried a set of IEMs and headphones and in both cases the buzz was present, though it sounded louder on the IEMs despite running them at a lower volume on the amp. The buzz is still not that loud either way and is at a mid tone kind of sound, not low or high pitch.

I found a similar mention of this from a 2018 relating to the Topping D30 (hence posting this in the DAC section over the amp section) but they never proposed a viable cause or solution.
Link: JRiver Media + Topping D30 producing intermittent, mid-pitched 'tones' | Audiokarma Home Audio Stereo Discussion Forums

Any and all help is appreciated.