The boot priority just means it will look for arm9loaderhax.bin on the SD card before it will try to load it from the CTRNAND. If you followed that guide, step by step then you would have copied it there. However, if you put the correct version of Luma on your SD card, it should boot that, not the one in your NAND. If it is doing that, it doesn't seem to be reading it from your SD card. Are all your games and stuff showing up? If so, then your SD card doesn't seem to be the problem so perhaps a corrupted file..... Though if you're really using the correct release, it's the ONLY arm9hax.bin on your SD card, your games are showing up and it's still saying you're on v6.6 when you used the 7.0.5 release, then something else is going on entirely.