Changing dimension(for example nether to overworld) sets the target dimension's entities scoreboards to 0.

How to reproduce:

1- create a void world
2- create a scoreboard
3- summon an entity and make sure it is unloaded when you go to the nether
4-give that entity a score
5-make a trip to the nether and come back
6-if, as soon that to come back to the overworld the entity gets loaded, is score goes back to 0

May be hard to reproduce