As I can only post one message a day and it's also not possible to edit one of my earlier posts, I choose to follow up here as this is the topic were I initially posted the issue with my cubox-i.
I followed the workaround/switch to distro boot/ extlinux boot option as described in: Cubox I1-300-D: initial Armbian flash screen, then "no signal"
Initially with the exact same image, the standard Armbian Ubuntu image Armbian_20.02.7_Cubox-i_bionic_current_5.4.28_desktop.7z, then:
- Created the extlinux directory in the boot directory of the SD-card;
- Added the ex