Having the problem here on 3.2 as well. Looks like it's been reported as MDL-59577 .
In reply to Joe Murphy
Re: Need to delete a student's Submitted assignment files M3.1
by Georgi Samaras -
Thanks for the link. Looks like this behavior is intentional, which is unfortunate as our workaround isn't really working for us as well as I thought.
No harm in commenting on the issue and watching it for future updates though.