End gateways not being symmetrical

So, I'm building something in the end, and I spent time and all that removing the end island in survival (save for the portal, and the 20 gateways)... But when I went to check out the gateways, I noticed something... While, almost being alligned.. They weren't. They are one block off. If I have an end gateway at X=96, Y=77, Z=0, then if I fly straight, and go to the end gateway that is opposite of this one, I see that the Z coordinate is -1
This is not only with that one, and appears to happen with every single end gateway. They should be paralel, no? If not, then my mistake... But it's just such a small thing, so I can't believe that this would be non-intentional. If it is, then sorry for the trouble!
Pictures attached down below (look at "Looking at block: ")