2017 Mack Anthem - MP8 Intermittent No-Start and Total Electrical Loss

I've got a weird one. Sometimes I turn the key and nothing happens. No dash, no crank, just dead. Other times it starts fine. Occasionally while driving, the gauges will sweep and all the warning lights flash for a second then go back to normal. I’ve checked the battery terminals and they are tight. I suspect a ground issue or maybe the ignition switch itself is going out. It's driving me crazy because I can't replicate it for the mechanic.