Some doubts that I have

[_AP]

Installation Guide

Did you use this? I’ve also have had issues, but to narrow it down…

Also:

Porting Drivers

As developers, we tell you you don’t need to move or copy any of these files. So I don’t know what you did, but that’s not the part that got things working. The only file that needs manual intervention currently is the EFI bootloader because we have not yet integrated that into the installation process. You can find it in /system/data/platform_loaders/haiku_loader.efi and it needs to be copied to the EFI system partition.

If you see PulkoMandy’s description of the location for the haiku_loader.efi, and then my reply to that where I moved the entire platform loaders folder. If you can move the platform loaders folder from the usb drive into the same path on the internal drive. Perhaps then it will work. But my setup was a little different. Try creating the efi partition and moving the efi file there.