You have to change your log in name if it is shared across ANY server.
I've had this name Xonra since I joined League in 2010 or 2011 (it's been so long honestly don't remember)
There is some random lvl 1 account on EUW that has never even played a single game and was created in 2015 (not by me). Apparently 4 years is long enough to keep a name, but since there is a rando, zero games played lvl 1 account on EU west, I can't use my own name as my log in anymore that I've had longer than this lvl 1 abandoned account on an entirely different server.
Pretty bullshit Riot.
I checked every single server from PBE to all live servers and this one server has a person that apparently made an account and never used it. lol What a bunch of crap, I'm so pissed about this. I use this name for everything game related as a username for like 2 decades now. Why do I need to change it when I'm not even sharing a server with these people?