1. Open KDE “System Settings” and navigate to “Input Devices”.
2. You will find the “Keyboard – System Settings” like in the following screen shot, if you haven’t done any changes in it any time before.
3. Now check “Configure layouts” and click “Add Layout”. Fill the upcoming pop-up with following settings and click OK.
4. Now the German keyboard layout is explicitly set, and used for all programs, after clicking “Apply”.
With this configuration the passwords are typed correctly by KeePassX auto-type.