I was in my survival world, trying to transfer villagers from a local village into a villager in my home. I decided to take a blacksmith. I pushed him through a portal I had built in the villager, and he went into the nether. I then went into the nether, and found the blacksmith and a farmer I had brought in. The farmer spazzed out and ran around like he was scared, and ended up walking into the portal, and traveling through. The blacksmith did not. He only stood there. In an attempt to bring him through, I pushed him back into the portal. He did not go back into the overworld, and will not leave the nether. This has happened before, although I never bothered to report it hoping that someone already had. I did a search and it turns out i believe nobody has. This only happens with blacksmiths with me so far.