Downloaded map incomplete

We are sorry to hear you are not happy with your results. It looks like only the northeast section was able to be rendered and the rest was filled in using the Flat Map Failover feature. You can read more about that here: 
https://support.dronesmadeeasy.com/hc/en-us/articles/360054457952-Flat-Map-Failover

The Data Collection guidelines that are agreed to at the time of upload state that you should use at least 80% overlap when dealing with trees. Bare trees are especially difficult to deal with so more overlap may be required. It looks like you used 75/70 overlap which clearly was not enough for this area. 

You can download the GeoTiff of the rendered area and then download the separate Flat Map Patch Geotiff. Those two files combined will be the same as what you see in the web map.