OK, As I checked the password for hundred times.... the username had a none capitol l in the .NET application. After changing to L .... the authentication ended up successfull....

To bad from me :(

Regards from the Netherlands.

I do not see any difference in your highly redacted logs.
Are you connecting from the same machine in both cases?
I suggest you enable password logging even in the GUI and compare the logs to check, if the same username and password is really used in both cases.

Hello, I'm still struggling with this keyboard-interactive failed error connecting via .NET assembly. Connecting via client goes well. I uploaded detail log for client as .NET.

The password does not have special characters.

I've have really no idea what to do, or setting, or ... :(