UUID bug

when i whitelist people then it's not the right UUID so they can't logon!
same with OP, and when i go in and change to the right UUID then it works, but only manuel.

I use command /whitelist add username:
what should happen is the whitelist add the username and the RIGHT UUID

What actually happened was...:
the UUID is not the right one, also when i have writed the username correctly with big and small letters

Steps to Reproduce:
1. it's all in the bug description
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