That was a bug in 4.16/4.17 when removing ISM it was not giving you index of correct instance. It always should in my opinion, otherwise you would never know instance you are interacting with.
But it was fixed so no worries 
That was a bug in 4.16/4.17 when removing ISM it was not giving you index of correct instance. It always should in my opinion, otherwise you would never know instance you are interacting with.
But it was fixed so no worries