[BUG] UUID problem with tablist plugins

Hi, I'm a developer of a velocity tab plugin. Some users reported a problem with your plugin as the uuid of proxy is different than the backend. This cause the player to be seen 2 times in tab. I tried solving that but this seems out of scope. This problem seems to show up only to premium users that used /premium. Here it's the issue https://github.com/WiIIiam278/Velocitab/issues/121.

To reprodure just install velocitab on velocity, join with a premium account and do /premium.
After the rejoin you will see yourself twice in tablist.
This seems to be caused by the backend not knowing the correct uuid of the user.

You can see all the screenshots in the issue linked above.
Thanks.