2 times login to KDE with the KDM ???

Hi @ all,

i’ve the problem, that i need to login two times with the KDM. When i login the first time and i hit enter, the screen change to black for 2-3 seconds, after this the KDM returns, and i need to login again. After that the kdm-login brings me into the KDE. The KDE is the original, i did not add some other repo. One thing i changed was, that i try to use my fingerprint sensor, but this doesn’t work, so i change everthing again to normal.
Someone has a solution, i can try, so that the KDM login works with only one time login?
Thanks

Greetings