@Blizzrdball I wonder if the SATA adapter could be the problem for you. I replaced my official Sony adapter's IDE connector with the Bitfunx brand SATA. I did saw somewhere that some other brands SATA might not work for PSBBN.
@LeoneFamily have you thought about trying to convert over to SATA and trying an SSD? I just recently completed my project and followed what Macho Nacho did, and I'm all good here, plus I was able to get PS1 games working correctly.