Issues with Blackbox and Firmware / Flashing

[Canadus80]

It seems, that I have an issue with my Blackbox MkII (the black one) and flashing / updating the firmware, or resetting it, when changing grips.

When I power up the blackbox, I get a blue and green LED. The F14 grip, attached to the Gunfighter III, works without issues.
I want to change the grip to the MCG Pro and want to flash everything, but that's when the problems start.

Above screenshot shows the VKBConfig at the start.
If I open the ZBootloader and it will look like below:

The No Bootloader Found Message irritates me. If I click on Boot, the blackbox will power down & not restart.
Something seems very off here & I am at the end of my wisdom.
Could someone help me out here and maybe put me back on track?

[fallout9]

There's no boot device because your device is not in bootloader mode yet, you need to select it, then click the Start Boot button. But, before that update your files; the VKBDevCfg version in your screenshot is very old and most probably won't work with the latest firmware. Here are guides on flashingand calibration.