Ciao, @veleno. It’s not clear what exactly you’ve tried or not tried, but I suggest starting over and following this updated flashing guide: Reflashing the Librem 5, Up-to-Date Tutorial .
Note that you need to start on a computer running a fairly recent OS version, (Debian, PureOS, etc.). Which OS is your computer running?
If you’re doing this on the microsd card in your Librem 5, I think you’re going to run into problems. I suggest following the tutorial I linked instead.
In that first screenshot, it looks like you are installing uuu too late, in the wrong order. Again, follow the tutorial.
Also see: Successfully reflashed, but at first no LED at entering Serial Download mode
P.S. When flashing, I’ve twice used the USB-A to USB-C cable that came with my Android, and it worked just fine.