Through search on the board I didn't see anyone mentioning this exact problem. I am using the App on an Android Phone(Galaxy S10 plus) Are you having problems uploading photo after cropping? My screen goes completely Black or it goes to the group photo screen but never completes. I then have to back out and crop again. BTW cropping has issues for me too. Dragging borders stalls sometimes. But back to uploading photos. I have found before you hit DONE on each individual photo, count to 3 slowly and the photo should upload fine.
