I was able to confirm these are coming from GCI students with all but one. Needless to say, mentors, please check to see if you might know that student.
I did ask the students I found (one student did most) why they thought ubuntu-manual-tests was an appropriate package to file against. If this has happened before and it’s happening again, it’s probably going to continue happening and we need to get to the root of it.
If I had to guess, I think it would be the link to “report an issue with this testcase” that’s perfectly situated to be right at someone’s attention:

Maybe it would be wise to change this to something like “report an issue with the wording of this testcase.” Or just keep it as is but link it to general bug reporting instructions. Or get rid of it altogether because the “detailed information on this testcase” already provides such a link.
The other problem we have is that those aforementioned general bug reporting instructions, at least as linked to the “file a bug” text at the bottom of the testcase seems to go nowhere, at last for some testcases, especially the least used ones (like those on the package tracker— see my concern about using this).
The text is in orange. I’d expect them to go there first. But in lieu of not finding anything, I could see them scrambling for a solution and just clicking on the closest “report a problem”-looking link.