I have followed the official guide (https://www.raspberrypi.org/documentation/hardware/raspberrypi/bootmodes/msd.md) to boot my Pi from a 8GB USB stick.
I have verified the correct bit is set in the OTP memory. I have copied a fresh download of Raspbian to the USB stick with Etcher.
Now when I insert the USB stick in the Pi (without any SD card) and power on, the first 5 sec nothing happens, only the red LED is burning. This is expected.
After 5 sec, I can see the activity LED on my USB stick flashing for approximately 2 sec, then it stops and no LEDs flash on the Pi / there is no output on the screen, and the Pi does not boot.
Are there any other steps I can take to troubleshoot this issue? What should the partitions on the USB stick look like? Is it connected to what model of USB stick I'm using? (Kingston Technology DT101 G2)