When I take a horse through the nether portal the score is completely removed. Tags stay on the entity.
Steps to Reproduce:
Create a scoreboard objective
Set the the objective to the sidebar display
Summon a horse
Use the scoreboard command to give the horse a score
Give yourself a lead
Attach lead to horse that has a score assigned
Step into a Nether portal
Observed Results:
The score for the horse is no longer in the sidebar
Expected Results:
I expect the score to still be there.
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Steps to Reproduce:
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2.
3.Observed Results:
(Briefly describe what happens)Expected Results:
(Briefly describe what should happen)
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Steps to Reproduce:
1. Create a scoreboard objective
2. Set the the objective to the sidebar display
3. Summon a horse
4. Use the scoreboard command to give the horse a score
5. Give yourself a lead
6. Attach lead to horse that has a score assigned
7. Step into a Nether portal
8. Once in the Nether observe that the score for the horse is no longer in the sidebar
Observed Results:
See #8
Expected Results:
I expect the score to still be there.

Attaching video from MCPE-173642.