Board Thread:Game Help/@comment-26398323-20150514085403

I'm playing on 360 and I just started hard mode a few days ago. I'd heard that hallow will stop corruption and is generally preferable to crimson/corruption. So I spread hallow all around my house using seeds and holy water. I lost a few npcs during a blood moon and now they won't come back. Is this some sort of glitch? And yes I have plenty of housing and conditions have been met. I'm stumped. 