Without other usb devices the keyboard works immediately. With them it takes 5 ish seconds for it to start responding. This is regardless of which device is discovered first (which I can manipulate), it seems to just wait for all of them. Is there a way to make it not do that?
How would bios change how linux loads usb devices?
There are lots of BIOS options that impact USB devices, and especially input devices. I’d start digging. If anything, I’d try plugging into the USB ports that are connected to the main bridge at the top of the board, and not any that are extended via passthrough cable. On some boards, those USB ports are set to emulate PS2 serial.
You never know how the kernel would behave compared to how the BIOS is setup. There might be some bios settings that force the kernel to behave a specific way.