JimStoneCraft
Comments
I've made a test planks_oak.png and added some screen shots, it's much easier to see the texture shifts when the gate is opened and closed in the Positive Z (South) direction, I don't think it's anything to do with the uv-lock.
I'm sorry but this is not a duplicate and has only come about with the new block models, it has nothing to do with false hitboxes and it effects gates between fence posts as well as cobblestone walls.
Did you even test it in game?
The gates work fine in 1.7.10.
After some more testing this issue can be easily fixed by uvlock to the 0 direction, I've attached the fixed fence_gate.json and the original version also (fence_gate_old.json).
This would also have to be done for the other five types of wood too.