FiveM stores nothing in GTA 5 directory.
It seems to me that your attempting to ban evade. No new “player id” will fix a bug. And the server more than likely uses your steam and game license identifier. Meaning, without buying another copy of gta and a new steam profile you wont be getting a new “player id”
If you can join other servers with out getting the “major bug” then its the server you are trying to play thats broken. If you get it on all servers then post what the issue is on the forum.