Establishing Delegation Boundaries

I’m in the process of establishing boundaries with regards to what my team delegates to me/what I’m involved in.

However, during this phase, I’m still feeling frustration when it’s believed that I will automatically help with something, and truthfully, I don’t want to help with a specific task (i.e., either out of the scope of my duties/I’m not the best person for this task/insufficient time/low priority in my schedule/concerns that need to be resolved).

As a result, I stick up for myself and re-clarify expectations for everyone. However, I don’t understand why I’m having mixed feelings. Is this normal as we are moving from 1 model to the next?