The app behaves differently from moodle in regards of how main page feedbacks are being handled.
Working path: /mod/feedback/view.php?id=6
Not working path: /mod/feedback/view.php?id=6&courseid=2
The latter works with the normal webpage but not in the app. The app returns "Module not found".
The reason could be that the app tries to get the module with id 6 from the course with id 2.But it has been defined on the main page and is not page specific.
In the web moodle this works as the courseid is optional/informational, only, and just ensures that the feedback given is linked to a course. But it does not check that the feedback is defined in the course itself, which in turn the app does.
Either getModule in course.ts could check if the module is on the main page (in course with id=1) and return it from there, or in form.ts CoreCourse.getModule could handle the module not found exception and add some specific logic.