Dense SfM leads to sparse Mesh

[fu1199]

Hello!
I have taken about 1.3 k images from a rooftop with a drone and want to reconstruct the scene with Meshroom. The SfM data looks really dense, but the Mesh of the same scene is extremely sparse with a lot of holes inside.

I am a sort of lost how to adjust the parameters in order to get a finer mesh. It seems like the Mesh is good in regions with less points than in regions with high point density.

Thanks a lot in advance for any help!