I have spent well over 2 hours on trying to boot my Pi 3B with USB. From what I have understood, as long as the program_usb_boot_mode is set to 1 you can simply plug in the USB and boot. However, in my case, nothing happens. I have a seagate 4TB expansion HDD with its own power supply. When I plug it in and start the Pi, the HDD "boots up" and I see the blue power light. After about 5-10 seconds, the HDD shuts down and nothing happens. Anyone know what the problem is?
PS: vcgencmd top_dump | grep 17 gives 302000 etc (correct output)