Nether portals aren't teleporting correctly

When loading into a world, the first time you go through a portal since loading into a world doesn't teleport you correctly, to be specific, it isn't multiplying or dividing the coordinates by 8. I went through a portal and it put me in the nether at the same coordinates as I was in the over world, and when going back through it divides the number by eight and sends me somewhere else in the over world than I was previously.