Currently, Canvas Student places all notifications into one system notification on Android. This can lead to notifications stacking up because you cannot dismiss them one at a time. This also makes it difficult to figure out what a previous notification is referring to as the entire system notification will only link to the most recent message.
Here is what a notification currently looks like:
As you can see, I can't expand this notification to see each assignment that has been graded. Tapping this notification only goes to the item on the bottom of the list. I also can't dismiss older notifications in this list, which means each time there is one new notification, it just expands this notification instead of creating a new one.
Here is the Android Development guide on bundling notifications:
Create a Group of Notifications
I believe this will help users get to specific places in the app that a notification is referring to. As well as allow users to leave certain notifications "unread" in the system menu so they can remember to do something later regarding that notification.
The current setup feels like a bug, but Canvas Support said it's working as intended and should be posted here. Let me know if I need to explain this better. Thanks!
TL;DR: Use Android Notification bundling instead of pre-bundling the notifications in the student app.