Hi VentureUAV,
what angle was used for this as oblique? Is this just a point cloud? Did you tried to compute mesh?
Wingtra is a drone, which is capturing images just from above, if I know it right. In this case for better modeling you also need images, which will capture the walls from perpendicular positions. In this case, as you have the images just from the sky, it is not sufficient to create the walls correctly.
Also, it seems, they are white, so there could be a problem, that the walls are featureless and then it is not possible to create a model there.
You can follow this tutorial for image capturing: https://www.youtube.com/watch?v=9e_NLp_FaUk&t=202s