Anvil falls shaked

I will open the first world "Asian countries" and the second "Render test position". I will try dropping the anvil in the first position x / y ± 18,000. But the results fall displaced in any direction then remain in the y / z position. (Example: if the fall of x / z ± 0 0, it will be displaced by one block (for example, shifted to x / z ± 1 0 and will return to x / z ± 0 0). Not only that position, when opening Render test position, the result is the same as x / z ± 0 0, and the result shifts also in any direction. [Only happens in anvil]