We are using "Delegate to servlet container" as access control for Jenkins in combination with Waffle because the users use smartcards and not a username/password.
When using the latest LST version os Jenkins (1.580.1) we are having issues that users get an the same UserID as the name "DOMAIN\Username".
This results in not being able to edit the user and not being able to create views or projects since it will try to open an URL with a "\" in the name.
In our current Jenkins environment (1.509.4) the "\" of the name is translated to a "_" in it's UserID and therefor it works fine.

I've tried both upgrading our existing environment to 1.580.1 with the same plugin versions and installing a clean 1.509.4 environment, which both resulted in the same problemens as mentioned before.
I could not find any solution for this on tje Jira board, so hopefully anyone has an idea how to solve this.