Cannot rename or delete clients from urbackup

I have a PC for example named “FirstComputer”. That computer has a urbackup client installed. Everything works, i can see the FirstComputer in my web gui.

Now the computer has to be renamed to SecondComputer. Everything is okay, in AD, pc…everywhere it shows new name.
But NOT in urbackup. Why?

If i delete the client from the web gui to reinstall it with a new name. Then in a couple of days the old name reappears. How can change computer name easily with urbackup also showing the new client name?
And how to stop these deleted compuers reappear???
Ive read documentation and theres no info about that.