I was talking about a similar thing with ICEx today (since he experienced it too).

It's a while that in arena seems that effects linked to secondary stats are showing weird behaviours.

Angel god konans with 100 chakra or kurama narutos with the 80% combo boost from the passive that fail multiple times in triggering the cd reduction.

Hans or kimimaros that fail in dodging the first standard attack.

Critical hits delivered with excessively high chances.

An excessively high quantity of control fails from mysteries or standard attacks that deliver controlling effects and so on.

It's at least since assist links introduction that those weird behaviours are going on.

P.S. Just to state it bluntly... up to 4 months ago the amount of control fails i experienced in arena was 0, the same was for the quantity of times that naruto kurama failed in triggering the cd reduction if the passive was up.

0 over 1 year of kurama constant use and 0 control fails over 2 years of previous arenas. Since november i get them once every 10/15 battles.

in shark bomb teams all the controlling effects, usually, last for 1 round (never saw an itachi susano'o or shisui used together with water main).

at most what may happen is that kakashi replaces chaos with immobile, but this, if possible, further delays the duration of the effect, unless the immobile gets a control fail, but in that case chaos remains.