As noted in the Data Collection guidelines that are agreed to at the time of upload, we generally recommend using at least 75% overlap to get good results.
The gaps you are seeing are either related to the terrain you are mapping being higher than the takeoff point at which the overlap pattern was likely generated for or you could have your camera parameters in there wrong or something. Check your focal length setting.
The bottom line is that your overlap isn't nearly enough. It looks like 40-ish%.
