If I have set MinValue and DataSource.Enabled = False then MinValue is displayed. Expecting an empty field. At most 0.

Correction. I always see actual values.

I tried

procedure TfrmsubMeterPenalty.btn1Click(Sender: TObject);
  Active: Boolean;
  Active  := not dsMeterPenalty.Enabled;
  fdtblMeterPenalty.Active := Active;  // Nothing happens without it
  dsMeterPenalty.Enabled := Active;
I only have 4 TDBAdvSpinEdit on the form!
In other cases it is OK

I'm sorry but I do not understand your question.
What exact settings do you use for MinValue , MaxValue & possible other property settings that might affect the behavior and what exact supposedly incorrect behavior do you see?

It looks like I was able to display NOT NULL data by some miracle, and they were NUll :( I have no other explanation. It works right now.