Thanks for replying! Yes, it seems a bit out of the ordinary (the Vero doesn't come with Android, but with OSMC (Linux) preinstalled). However, I've seen reports of people successfully booting from SD card, so I tried those first, but they didn't seem to have this problem.
Would a USB-A to USB-A connector work? Or do I need USB-A to UART? The Vero doesn't have such an external port, so would I need to open it up?
It does have a separate USB connector that it can draw power from (without PSU) and connect to a PC.
I failed to mention that I purchased a USB-A to USB-A cable to try this (IIRC this was mentioned somewhere in the OSMC wiki).
Though, when I connect it, it doesn't show up either in lsusb or dmesg. I tried different ports and different PCs. The Vero does boot using this cable, so something is working. Am I missing something maybe?