Why Davies-Bould chose a number ob cluster higher than Silhouette or Calinsky Harabasz?

I am doing use several metrics in order to know what number of clusters is correct in order to do this I selected 3 clustering algorithms and 3 internal evaluation metrics, Silhouette, Calinsky Harbasz and Davies Bouldin.

The results of this was the following:

      S    CH    DB
Kmean 3    3     9
Agglo 2    2     9
Gauss 3    3     10


The original dataset has 3 groups, and in general S and CH works well, the questions is what DB always returns a high value for the number of clusters?

Thanks