Hello @PBB1956
The first issue there could be the used drone and its GPS precision. As it seems that you are flighting quite low and close to the buildings, the precision could be also low and this can influence the alignment.
The effect of altitude basically influences of the resulted model precision and resolution. As from the higher altitude, the detail of the model is lower and also the precision.
Oblique images are helping for the models to get better height detail, as you are adding also images, which are looking at the model differently.
These posts can be also helpful:
