No power to three Pro cameras… what am I doing wrong?

Last week I tried to setup the Nanit Pro (with square stand). Plugged the camera into the stand, and the stand into an outlet — then logged into the app to begin pairing — but the camera won’t turn on. That is, nothing lights up when I plug it in, and nothing happens when I press the WiFi button.

I’ve received two replacement cameras via Nanit Support, and I’m having the same issues with those two.