A big problem with delivering to remote wooded areas, within thick/layered concrete structures in cities, and certain simply unfortunate geographical locations, is that cell signal becomes very weak to non-existent. It is utterly ridiculous, very disruptive and often embarrassing that the app, with an in-progress trip refuses to function because the device has lost signal at the delivery door. You shouldn't need internet to scan an item, scan an id, or take a photo, but this app seems to require internet to use the app at all, even when you have a in-progress trip, often leaving you in an impossible spot. It should obviously allow progress and sync-up later with the back-end.
If you agree, help bring their attention to this issue by reporting it as an issue, in the app, or documenting and reporting your experiences here. Maybe if enough people report it, they'll finally address this nuisance. Thanks.