MC-68015 has nothing to do with this issue. MC-68015 is talking about a "glitch" where you can go past the world border at x/z 29999984. That is intended. However, I am talking about the invisble barrier at x/z 30000000, not the one at x/z 29999984, which is probably a bug.
Hey mod, MC-68015 is not a duplicate of this issue. Please remove it from the duplicate list.