Solid yellow LED

I’m trying to set up a Home Assistant yellow.

It’s a brand new kit, with POE, a new SSD, and a new Compute Module 4 - (8GB RAM, 32GB eMMC, 2.4/5.0GHz Wi-Fi & Bluetooth 5.0) (CM4108032).

I installed the SSD, CM4 and heat sink, and imaged a USB stick, per instructions.

When I try to install, the yellow LED flashes 10 times and then stays solid. Red is solid, and green is blinking periodically.

It is on the network, and responds to a ping. It does not respond to an http request,

Not sure where to go from here. I can’t find anything about “solid yellow led” except some indication it’s a network problem, but it seems to be joining the network fine. There’s no reason why it shouldn’t be able to route to the WAN.