If I plug in my external hard drives they work fine, but if I have them plugged in at boot they do not show up.

They are external hard disk caddies that I have put hard drives in.

The same happens if I try one at a time.

lsblk only shows the mmc devices of the pi

ls /dev doesn't show any "sdX" drives

adding dwc_otg.speed=1 /boot/cmdline.txt didnt help

dmesg doesn't seem to show them, but there are a few items with usb in the name output below, as I don't understand it all fully.