Nether Portal Bug?

I have three portals in my world!

 

Coordinates:

-774 ~ 1305 = Main Portal

-603 ~ 1052 = Gold Farm Portal

-41 ~ 1421 = Mob Farm Portal

 

Nether Coordinate: -105 ~ 159

 

Is this a bug or it is introduced or a new feature in the game that I only have 1 exit on the nether even though I have 3 portals in the overworld? The point is I have a thousand gaps of my portal in my overworld but I only end up in the same coordinates when entering the nether.