Hi!

Thanks so much for bringing this up. As you said, although Kimimaro has a passive that allows him a chance to block attacks, it is not 100%. Also, another thing to note is that the rules that pertain to ninjas are different in the Ninja Exam. What this means is you will face ninjas in Ninja Exam which can have slightly different passives then what is available.

For example, you will sometimes find yourself facing ninjas who should not have immunity to debuffs but do.

Ninja exam is here to challenge us and will have ninjas different from what we are used to. It is not a bug =p

Hopefully that helps and makes sense.

For the future though, if you do find a bug or have a support related inquiry, please use the bug/support section found here. Thank you!