Sorry if this has been asked before. I use Moodle 3.6. When students make changes to a submission, they have to delete the old assignment and upload the newer one by clicking "Edit Submission" and it seems like the newer submission overrides the older one. Is there a way to view the history of all submissions versions and download the older versions?
If, however, students are simply editing their submission multiple times before it is graded, then there is no way to see the different versions they uploaded.
So the behavior you are explaining above is expected when the assignment settings are set to "No" for Require students to click the submit button.
This means it's one assignment that they can constantly edit (or delete their file and replace it with a new one).
So, you'll instead want that setting set to Yes.
This means, once the student uploads their file, they then have to click a second button, Submit" (like in a quiz). Then, when they go to submit again, they can either "edit and resubmit" their previous file, or "submit a new attempt" - and if they submit the new attempt, then you see a running history of each submission on the individual student grading screen.
I just wish you could block a student from editing the previous attempt - our students see the screenshot below and always get confused on which button they are supposed to click on. I wish it just was always the "submit a new attempt" button.
Resubmit based on previous attempt doesn't change the previous attempt, it just gives students a copy as a starting point.
For file submissions we don't generally find this useful; the student will have their old file anyway, or even a feedback file with some teacher comments on it from which to compose their new attempt.
When using multiple submissions; you need to set up the assignment submission settings to determine how new attempts are created; manually by the teacher, or automatically until pass (in which case the passing grade needs to be set under Grade settings). There's a maximum attempts setting as well.
Previous attempts are visible on the grading screen by scrolling down to the bottom.
If you use multiple attempts, especially with automatic reopening, warn the teachers what to expect-- otherwise it looks like failing marks dissapear.