Game only targets one entity when more than one have the same UUID

When two or more entities in the same world have the same UUID, the game only targets one of them.

What I expected to happen was:
All the entities got targeted

What actually happened was:
Only one entity got targeted

Steps to reproduce
1-Summon an entity with a custom UUID tag (For example 1-2-3-4-5)
2-Try to execute an action with it (like killing it)