Weird, I'm trying a test with a PUP (finds passwords), it is only 31KB and from the interface I see that the Submit button appears Greyed out to start with the Cancel is the active button.
It shows the file will be submitted on the next Update. I did a manual VPS update and I did see it being uploaded, but being so small a file I didn't manage to grab a screenshot. It appears to have gone up OK.
I just wonder is there isn't some sort of internal limit to what can be uploaded - if there is, I would expect be to get informed of that.
EDIT Typo.
Hopefully a reinstall will resolve it.