That happens because there are various control components and buss bars inside the distribution box. They route the power to the various items and have some control over items by using circuit board mounted relays and transistors to do switching being controlled by processors inside the box. They can fail or get corroded internally and suddenly things stop working. On some vehicles it is even worse, to the point that the power controller has one small item fail and now the horn doesn't work, or the right hand high beam or the left rear turn signal. The attached images are what is inside many modern "fuse boxes" these days as companies work to make assembling cars faster as they add on more and more options.
Images (Click to make bigger)
Monday, March 29th, 2021 AT 12:21 PM