When connecting to a robot in Robotstudio, it asks which user you would like to log in as. This is a list of all users that are on the current as well as previous robots you have connected to. This can be confusing and makes it difficult to figure out which users are valid users to log in as across multiple controllers.
The solution to this is to not store a history of users, but instead refresh the list and only show valid users for each robot that you connect to.