Can username change automatically?

Hi, sorry if i make a mistake, i’m not a native english speaker.

We use jitsi to have classes, a friend come to realice that someone has the same name than his, we first think it was an error (same thing have ocurred in other classes) but then “he” started to write in chat, asking questions, nothing bad, but it wasn’t my friend. After the class we asked if some did it, thinking that was a prank, but no one did it. Is it posible that the system change (or copy) the name by itself?

On a standard Jitsi installation you can pick any name you want.