I think you are running into a common “issue” with Sharing (Shared access)… which I believe was initially developed as a quick way of demoing your basic project to others without commitment of Login/Passwords, etc.
However, I don’t think it was ever meant to work with some of the new Widget interfaces that you and others keep trying to use with Sharing. Until the developers determine if a revamped/updated Sharing option is to be availed, you just can’t use a shared phone with all Widgets.
If you want TRUE multi phone/tablet control with a single project, use the same login for both devices. If you don’t want the other user to have access to your other projects, then create a seperate account just for that project.