Snakepit Pearl Ring Bug? POE2

So, I am currently running a frostbolt build using snakepit for the unique ability "Projectiles cannot pierce". The problem is the projectiles sometimes pierce and sometimes they don't but most frustratingly the projectiles don't even explode they literally just bounce off the monster when it does hit and only explodes when it hits actual terrain or frost wall etc. Is this the actual intent of this unique or is something wrong with i.e. bugged? I have xbox video clip but don't know how or where to upload to show the problem.