End crystal beams look glitchy and are offset relative to the end crystal if the beam target location is far away.
Effect increases with distance, and occurs in all dimensions and in all of the orientations that I tested. This bug occurred in both single player and multiplayer, but the multiplayer server was not vanilla.

To recreate this, run /summon end_crystal ~ ~ ~ {BeamTarget:{X:30000000,Y:0,Z:0}}
or /give @p bat_spawn_egg{EntityTag:{id:"minecraft:end_crystal",BeamTarget:

}} 1