Value in User Table "Disappears"

When a column is assigned as a role column in your user profile configuration, you can only assign it if the user adding the row has the same role. Otherwise you need to use a server side workflow to assign it.

It has nothing to do with the the name of the column. A role column relies on actually assigning that column as a role column in the user profile configuration.

Also keep in mind that using a non role column as a role column does not provide the same data security as a role column with row owners. Using a pseudo role with a filter just hides data. It does not protect it.