Any non-player entities entering end portal in the end dimension will be teleport to the high sky

Once I entering the end portal in the end dimension,I could back to the original point of the overworld,but other entities will be disappear after they enter the portal.So I let a named armor stand enter the portal first,then I enter the portal,too.After I back to the overworld,I teleport myself to that named armor stand,I found that I have been teleported to the high sky, that armor stand should be appear at the origonal point of the overworld.