Error 9 during restore indicates a data communication failure; a charging-only USB-C cable lacks the data lines required for DFU/Recovery mode communication, which would cause this exact error regardless of PD wattage support.
Use a certified Thunderbolt 3/4 or USB 3.x cable with full data pins (not charging-only), ensure both ports are debris-free, and if the issue persists, attempt the restore from a different Mac or Windows PC with iTunes to isolate the host.
iMac 24″ M3 (16GB) | HomePod mini Stereo Pair
Dublin, IE | "Clean Wi-Fi multicast fixes half of AirPlay drops."
