I have tried to boot the rockpi4 into OTG flash mode. The switch is set to D, the USB A port connected to the top most USB-3 connection, the other side of the cable is USB-C connected to the computer. I have tried connecting this to a macOS machine and a RaspberryPi running Arch. The eMMC was connected without a partition (none recognized on other systems). I tried removing the eMMC and still nothing. The power was connected after the USB cable was.
I did notice one quick connect and disconnect (reported by the kernel) on the Arch system but have not been able to get that since.
Any suggestions as to what is happening / how to fix?