Official comment

It looks like the area you uploaded has a lot of trees in it. Only 70 of your 129 were able to be stitched so it is likely that you defined some GCPs in some images that weren't included in the map. If there are not 3 solid anchor points there is nothing to scale it with and it can be whatever rotation minimizes the error between the defined points.
You could probably get this job to work without the GCPs using the EXIF workflow but that won't help the images being included. Overlap is the only thing that can help you here. The bigger the treed area you want to include, the more overlap you should use. the 70% setting in the app is pretty minimal. It would likely work but the trees might not render well. To get an accurate rendering of the trees it helps to use the High 80% or even the Ultra 90% setting.
Based on your other jobs, you clearly know how to use the GCP tool, so it is just an issue of getting the treed areas to be included in the stitch.