I’ve built 3 raspberry Pi3B-HiFiBerry Dac + rigs. They are housed in 3d printed cases I designed myself. Two are at home feeding hi-fis in different rooms. the third is at the shop. It is connected to the main router through an extender to which the NAS containing the mp3’s is connected via ethernet.
It worked fine for a couple of years then started disconnecting from the network. I assumed that the router was doing it and tried everything I could think of but no success. I would disconnect the RaspberryPi from the 5 volt power feed, reconnect it and it would run fine for periods from a few hours to 20 minutes. sometimes it would reconnect after a pause but other times not.
It suddenly occurred to me that the trouble started when I upgraded the receiver it sits next to from a Nakamichi Receiver 2 to a Receiver 1 (more oomph to drive my AR 3s)
MInd you it took me almost a year to figure this out, problem apparently was that something in the Raspberry Pi didn’t like its location next to the receiver. I relocated it about 6 feet from the receiver and the drop out problem is completely gone.