I got it up and running after I removed and reseated the Preenf405 chip. For some reason, it was showing the bootloader showing that it was connected but it would not boot until I reseated and soldered the chip in place.
I do have an issue with the screen display. Between lines two and line three there are lines above the characters. Is this normal or do I possibly have a bad screen/ connection with the screen?
I'm having the exact issue you describe, I can get the bootloader running and boot into the bootloader mode, but I cannot boot normally, I just get the full blocks in the OLED. I have a self-made preen405.
I removed the preen405 and put it back in, but it did not help. Did you say that you soldered in place in stead of using the socket?