This is reproducible stable to a 100%

I open my session. I open Kontact. 
As the kmail account passwords are stored in wallet with kgpg, I was usually
asked the password one time. Then it opens, fine. 

Now, observed behavior: 
you input the password, the password is not accepted (I did proof this by
watching every stroke, it is(!) the right one). So I do a repetition of 8 time
of the password input, trying again and again. At a point then suddenly the
password is accepted.
You can now work with problems as the wallet opened with the very password it
claimed was wrong before. 

Desired behavior: kwallet should open with the password after one input. 

The only particularity is to be seen when you use an external screen and
keyboard. This should however be unrelated but is mentioned for completeness:
If your password input of kde is on the external screen it will jump at the
refusal to the laptop screen. However, the input from the external desktop is
correctly taken (at least the "dots" appear in the window). 

Kwallet settings: 
- only one wallet for local and internet. 
- kgpg signature with 4096 RSA (no email address as this signature is used for
wallet only).