It’s been closed because of the ‘use of consumer devices’ off-topic limitation.
I have objection to this.
The OP is asking about a question larger than the ‘use of a consumer device’ itself. It’s fundamentally a system noise issue, and it’s common one when it comes to dealing with power supplies running powerful motors. In other words, it’s a real engineering question, in a subject area near and dear to many of us: electomagnetic compatibility (EMC).
Would it be any different if, say, OP had hand-built an R-pi with a touchscreen and encountered the same issue? A long while back I answered a question like that related to IR sensors, and the answer was similar: suppress the common-mode noise from the supply. Clearly, it’s an EMC question.
This question, also closed as off-topic: Two devices sharing the same coaxial cable, what frequency channel should I chose? involves the use of cable modems, antennas and MoCA together in a home wiring plant. Again, although it involves ‘use of consumer devices’, it is about system design: specifically, RF compatibility between Cable, OTA TV and MoCA. Again, it involves EE. This application may not be near and dear to you, but as a former STB/DVR/MoCA/DOCSIS designer it is to me.
And it goes on and on. As engineers, hobbyists, hackers (and often all three) we design and troubleshoot systems, many of which involve integrating consumer electronics and making them work.
My point is, just because a ‘consumer device’ is being used in a system doesn’t automatically mean that it’s about the use of the device itself. If the scope of the question includes scope beyond the sub-unit, and the question is an electrical one, it’s a EE question and deserves to be on-topic.