Zalmarath the Colossus invincibility bug

On character HCSSFTOTEMTITAN I experienced an issue where Zalmarath the Colossus became invincible for an extended period of time. This is not the first time I see it and it seems to be related to totems somehow. I have not seen this on any other architypes, it seems that shockwave totems cause the boss to become immune to damage. At that point not only totems but basic attacks or other skills stop effecting him. From there 2 things occur: 1 after some time he unbugs and starts taking damage, I don't know how, couldn't find the exact trigger, 2 he just stays invincible and you have to exit and wait for the instance to close, because you are softlocked. So yea look into shockwave totems and how they interact with him, I have not have this issue with any other bosses.