All students are "Late submitted"

Every single student is listed as "Late submitted", both those who submitted before the deadline, and those who submitted after the deadline (which was not set to "Cutoff", so it's no surprise that some students submitted afterward).

At the time of this screenshot, the deadline was 16.5 hours ago, so NONE of the students in the screenshot should be listed as late.


I note that the Assignment-editing tooltip says I must use a non-ISO-8601 date format, but I'm not American, and the date picker actually does not give me American dates, it gives me correctly localized ISO 8601 dates. So maybe that's the problem?