[Koha] Self-checkout behavior

[uwe]

Hello,

I have a question to the self-checkout-module. As documentated I
enabled in the preferences "AutoSelfCheckAllowed" with
"AutoSelfCheckID" (a special user with circulation rights, for example
"MyCheckoutRobot") and the "AutoSelfCheckPass".

Then I log in in the OPAC as a another patron (e.g. "Uwe") without any
rights and go to the self-checkout-page and log in too. If I now go
back to the OPAC I'm suddenly logged in as the in the preferences
defined user (in this example "MyCheckoutRobot"). 

Perhaps I don't understand the module. But how can I prevent the user
change in the OPAC from "Uwe" to "MyCheckoutRobot"? What I only want is
that a normal patron can use the self-checkout-system.

Thanks and best wishes
Uwe