Hi,
What are your camera reprojection errors? If they're high, you most likely still have an alignment issue which could be the cause of your incomplete dense cloud. You could try varying the key and tie point limits to try and fix it, as well as add manual tie points (markers) to improve the alignment.
There seems to be a lot of vegetation where you survey. I'd suggest a higher overlap (more images) next time, as vegetation is hard for matching algorithms. Also including oblique imagery has anecdotally proven successful for me in terms of vegetated areas.
I also often have issues with my region cropping the dense cloud output, due to it being too small. I see that the horizontal extent seems good, but could the region be cropping it height-wise?
Hope it helps.