Entity UUID's SHortening when Reloging

Put the summary of the bug you're having here

What I expected to happen was...:
The UUID to remain the same so that I could control entities through the scoreboard

What actually happened was...:
The UUID Shortened in the scoreboard and differed from the entities actual UUID. So when I used the selector @e[score_score_min=1] after re logging it wouldn't work when originally it would.

Steps to Reproduce:
1. Create an entity. (I used a Minekart)
2. Assign it a score on the scoreboard of 1 or higher
3. try this /tp @e[score_YOURSCORENAME_min=1] ~ ~5 ~
4. the entity should go up 5 blocks and fall back down
5. Relog your would.
6. run the same command. Now it wont work