scoreboard vuales disappeare when an entity travels to a different dimension

I teleported a creeper with a scoreboard value from the nether to the overworld.
its scoreboard value disappeared.

I tested it with portals and with a tp command.

both on a server and on single player tested

What I expected to happen was...:
The entity will keep its scoreboard

What actually happened was...:
it's gone

Steps to Reproduce:
1.create a new objective
/scoreboard objectives add test dummy
/scoreboard objectives setdisplay sidebar test

2. summon a creeper and give it 1000 score
/summon creeper ~ ~ ~ {Tags:[test],PersistenceRequired:
/scoreboard players set @e[tag=test] test 1000

3. get the creeper through the portal, the scoreboard vaule will disappear.
even when you go in afterwards, the creeper will be in the nether but its scoreboard vaule will be gone.