There are still questions from before 2.0
There are questions whose answer is only mostly true (not always) due to various fringe cases
And then there are questions that are flat out nonsensical, like the "which of the following appeared in the series" where the answer is purse (vs ramen, BBQ and dango I think).
I haven't ran into the bug 0-0-0-2 in quite a while, so I'm not sure if that one was fixed, but it was around for a really long time.
The quiz is just... not reliable in the least bit..
Anyway, getting off topic. This 5 vs 10 ranked thing was brought up when the monthly event was FIRST revealed, this was 2 month ago, nothing is done, so don't expect it to ever change. You really shouldn't be surprised that events discriminate against ftp, they always have.
@Einherjar: stop trolling.