Streaming Bridge freezing

Suddenly my Streaming Bridge froze and refuses to reboot with a power cycle. Both indicators next to the ethernet port are constantly lit, as well as the Stream OK indicator – even though the ethernet cable is unplugged. They return to the same lit state even after a few minutes of unplugged power.

And the device is nowhere to be found in any software instance, neither the ATEM setup (tried both via ethernet and USB connection) nor in the router's list of connected devices.

What to do? The factory reset is unavailable since it can't connect to the setup software. And it doesn't seem to be any hardware reset button on the device itself.

Update: I left it unplugged over night and it still comes on in the same frozen state as yesterday.