Since the schematic online is for a Rock Pi X version 1.3 board and these are version 1.4 boards, we do not know if there were any changes to the PMIC for the system. No information exists.
I have used at least 4 different USB3 SSD drives in various cases as there are many out there. One works all the time, two do not work and one is intermittent as to startup or disconnect.
So far the USB3 powered hub is a solution with all USB powered devices with the existing v1.4 boards I have. I thought it was the USB3 interfaces, but this looks like low power issues on the pc board side. No big deal, I just tell everyone to use a USB3 powered hub.
It would be nice to see the specs for the power output capability of the USB3 port on the Rock Pi X v1.4 board. The USBC connection auto-switches DC voltage as needed. Not sure about the USB3 version.