POE Hat DoA?

I just received my POE hat today. But so far neither of the two POE injection devices I have light up the LEDS on the Pi. I have one other device capable of injection coming in the mail today, so I’ll give that a go too… but I can’t seem to get anything out of it so far. If I leave the hat on, and plug in USB-C power, the Pi lights up, but the hat starts buzzing, so I’ve removed it for now. Any advice?

Ok… so it would appear, that the three Mikrotik POE devices that I had (which worked perfectly fine to power each other), didn’t work to power the device. Fortunately, I had some new Ubiquity networking gear that I had coming in today, and they seem to power it fine.