How do you stay calm when your co-parent keeps stirring things up?

My ex has a habit of turning simple stuff (drop-offs, backpacks, shoes, timing) into chaos. Every exchange feels like a test.
I’ve done the work .. therapy, boundaries, documenting, all of it.. but I still feel that stress in my body every time.

For anyone who’s been here:
When did it finally stop getting to you?
Did something click one day, or did it just fade over time?

Not looking for legal advice or “ignore him” replies ... just real stories or mindset shifts that helped you stop carrying it emotionally. Come on give a fellow coparent-er some help here :) PLZZZZ