So I have been messing around with the whole disappearing wall / ghost voxel issue and I have found that if you lay a wall down and then go back out of build mode and the wall is not there you can try this to fix the ghosting:
1. After you see that your wall is invisible go back into build mode and place 1 block on that newly created section that was invisible (this 1 block can be set anywhere on the new invisible section)
2. Leave build mode just for a second
3. Go back into build mode and remove that 1 single block you placed
4. Leave build mode and your wall section that had disappeared should now be visible
That's it! This works in most cases that I have tried. It's an extra step but it does work.