Am 01.10.20 um 00:19 schrieb Elliott Sales de Andrade:

Could it be a timing issue of some kind?

the sooner i hit the boot from usb button, after the stick got inserted,
the higher is the propability to start.

Are you saying you insert the USB stick _after_ turning on the
machine? Otherwise I don't understand the correlation between the
insertion and pressing a boot from USB button.

The working procedure is:

Power on
entering Bios
switching to boot manager page
inserting the stick
waiting until it gets powered on
swiping the usb storage boot entry to left
acknowledging the usb boot.

None working procedure:

Power on
Inserting stick
switching to bios
switching to boot manager page
swiping the usb storage boot entry to left
acknowledging the usb boot.
...
none secure boot message from bios
reset.

Marius