I’m just encountering the same issue on B01 Developer kit board as @Spenseryao (topic from: 19. Aug 2019.): cannot get to work BOTH: manual power button AND auto-power-ON at the same time.
Power button starts the Nano only if the “disable-power-on” jumper is set on J50. If no jumper: auto-start is there but power button is then useless…
Sorry if I missed the point of the accepted answer but how to make both features working at the same time ?