I have a 4-port USB 2.0 hub powered by a 5V 3.1A power supply that does not show up on my C2, with or without devices connected to it.

 

I have the C2's USB OTG port disabled as I use a DC power supply.

$ sudo lsusb
Bus 001 Device 004: ID 1df7:3010  
Bus 001 Device 002: ID 05e3:0610 Genesys Logic, Inc. 4-port hub
Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub

dmesg does not log the hub connecting/disconnecting. How do I troubleshoot this?

armbianmonitor -u: http://ix.io/1DzS

Do you have anything plugged into the hub when you boot the board?  This may be related to the other issue concerning partial power-down.

As I mentioned earlier, I have tried booting with and without devices attached to the hub, the issue persists.

What does it identify itself as on a system that recognizes it?