This is a forum for questions related to the bpmn.io project. I’m afraid we can’t help you with questions regarding Activity. Please make sure you’re asking in the right place before asking a question that seems to be very important to you.
I understand where I ask the question. I use not Activity, but Camunda. On their forum(and other forums) on these issues are often sent to this forum! Thank you for such a “polite” answer!