I've verified this using both the Student and Teacher iOS apps while acting as both a student and a teacher.
1. As a student, I use the annotation tools to mark a PDF within an assignment. I then turn in the assignment.
2. As a teacher, I can see the assignment was submitted by the student.
3. As a student, I can click on and view my submission.
Here's the problem...
4. As a student, I can press and hold on the screen to bring up another annotation tool bar. I can make edits on the submission. The original markings are flattened (cannot be changed), but I can make additions.
5. These additional edits are added to the submission in the teacher view with no new time stamp, as if the edits were existing for the original submission. However, the additional edits can be changed by the teacher, too, using the Teacher iOS app. I can move them around, delete them, etc.
These additional edits also show up in SpeedGrader on my computer, but they do NOT show up when I download the submission from the Gradebook.
What's going on?
Edited to add a screen recording showing this bug: https://bluej-my.sharepoint.com/:v:/g/personal/kthursby_ccsd_cc/EYFE4QOmZ19NjavrNE_KtI8Bv_aUaCxrg3p4ScoS6tHSGg?e=Z6UO2O
Running iOS 12.2 on a 6th generation iPad.