Thank you for the answers.
I will try it without owner-draw if I can avoid it, maybe there is something basic wrong.
This columns property was set to zero and the fields empty (I have an IBQuery with fills the DynamicGrid at runtime).
After I tried to add something at design time and clicked "add fields" (I am not sure and do not want to try it again), the Lazarus IDE set goodbye to me with thunder and fog.
In Delphi there was a field for DBGrid, which allowed me to choose "all query fields". Such a function I have not found in Lazarus / DynamciGrid. So may be, there is something very substantial missing in my code.
Please forgive me, if I mix up menues, queris and data-components.
This looks all similar to me.