If you have followed all the usual steps to unlocking the phone (bootloader unlock and oem flashing setting in android), you can just boot the phone into fastboot mode and use @piggz flash script. @piggz, could you advise if there is some hitch with a GX4 PRO?
As for the UBports installer, recent versions do NOT support flashing SFOS. Sad, but true
I have as a rule installed VollaOS first on these phones just to test that everything works and the android base is one that should be the same as the one @piggz develops the SFOS port with. So, my steps have been:
- Use ubports (or the flash.sh script) to install VollaOS first
- test hardware (wifi, calling, camera, bluetooth, etc).
- enter developer mode, unlook bootloader, allow oem flashing foo
- boot the phone into fastboot mode
- run the flash script.