Sometimes when an ArmorStand (i don't know if it is with all entities) is teleported, it updates in the game, but not graphically.

In the attached video, the ArmorStand is teleported away to be used as a marker, then teleported back when it's job is done, but on the way back, it waits a pretty long time to show that it has been teleported back, even though it has (i am not able to place blocks where it is supposed to be)