Villager Disappears After Putting Them Through Nether Portal

 I noticed that whenever I pushed a Villager through a nether portal in the nether going to the Overworld whether their in a mine-cart or not they only stay in the overworld for about a Minute then glitch and teleport back into the nether near the portal. This has happened 3 times within a span of 30mins. Hope you can fix!