General account username question

Hello, I made a plex account for my son, and when I tried to set a user name first and last name it said it contained invalid characters, its just his first and last name not numbers or special characters in it. but then when I try his first and last name all one word it says. it was already taken.

can someone from the plex team send me a message?

plex.tv usernames need to be “globally unique”, i.e. you are competing with all other plex users for common names.