Hey,
placing back the jumper to initial VEXT status - what is the behavior?
Pushing the ignition button can take 1-2secs until power LED is on.

You can repeat the flashing procedure to make sure it went well.
For update procedure there is the need to continuous power the serial levelshifters. That’s why the VEXT jumper should be moved to the 1st pin pair in “levelshifter” section.
The device will be started and powered as soon as you plug the USB cable into ASC0=serial FTDI.
After starting the update SW, push reset to trigger a restart of the device.
The update procedure will run in 4 parts.

ASC0 and TXD0 LEDs will start flashing for around ~6secs (core B will be updated). A ~4secs pause will come next ASC0 and TXD0 LEDs will start flashing for ~2secs followed by a small pause ~1sec. Then core A will be flashed for ~6secs (ASC0 and TXD0 LEDs will be flashing).
After these sequences flashing tool should show 100%.
Then replace the jumper to intial VEXT and startup device normally.

Hope this helps,
Markus