Map Waypoint dissapears after traveling over 256 blocks from map edge.

When traveling too far from a map(about 256 blocks), the player waypoint dissapears. Tested with the lowest level map in two worlds in 1.13pre-2.

In the pictures provided, the map was created at 0,0 in a superflat terrain for convinience, but the bug is there in normal survival worlds as well.