Looking into it, thanks guys, you are not the only ones to have this issue. I will have more info tomorrow on what's going on.
EDIT: Tried on my end, managed to reproduce the issue.
The fix: Wait more than 10 minutes between the two online submit. 12 to be safe. You can resubmit the second one, it must work now.
But yeah it's indeed a bug, it shouldn't said invalid ID but redirect to the previous valid like before.
Should be fixed next monday.