NHTSA Complaint #11533069 — 2021 TESLA MODEL Y

My family and I were driving from San Diego to Arizona on Interstate 8. I was utilizing autopilot (adaptive cruise control with lane keeping assistance) and 4 different times the car slammed on the brakes from approximately 75 mph to 60 mph. We were driving on a bright, sunny, extremely hot day (116 degrees). Luckily there were no cars behind us or we could have been rear-ended. It's also noteworthy, there were no cars/vehicles in front of us or objects in the road when the phantom braking occurred. I now no longer feel safe using autopilot on our Model Y. No warning messages appeared and no additional information was provided by the car. We have used autopilot on several other road trips and never experienced this issue.