Weird electrical issue

[Ctullu]

I have been noticing an issue since I installed my relay box. When powering off equipment with the relay switches in the cab, a pop comes through the speakers, and sometimes the sound through the stereo system will be distorted or stop all together when this happens. This includes when I move from park to drive (not sure if this is due to the backup camera powering on and off as I roll though reverse, or from the reverse lights themselves). It doesn’t seem to be causing any other issues, it’s more annoying that anything.

I have an aftermarket head unit, but never had issues until I installed the relay box.

Any ideas?