Name Changes Bug

Your username: ItzTomyz (Before it was Tomyskyblock)
In which minigame/server does the bug occur: Creative Servers
Detailed description of bug: So here it is, we have a problem on Creative that people who had changed their names, they can actually open Chests on Plots they aren't added...
This bug is making a lot of people needing to change their Chests to somewhere else or to hide them for another players that they don't want to use the Chests...
So here it goes some of pics:

• Image 1

• Image 2

Note that the names of the owner of the plot and some other players have been hided to protect their identity.
On this plot, I'm not added on it, and I still can open normal chests...

We need to fix this bug...
Thanks for reading.

-ItzTomyz​