NHTSA Complaint #11472818 — 2021 TESLA MODEL 3

Cruise control set to 75mph (speed limit) on lightly trafficked divided highway at ~5pm on June 26. Skies were overcast and temp was about 80 degrees. Car braked from 75 to about 62mph but did not disengage adaptive cruise control and neither did I by applying the brakes. There was light traffic and it did not happen while approaching an overpass which has triggered this before on two occasions. After rapid deceleration to 72, car increases speed but fluctuated in high 60s and low 70s before returning to the programmed 75. Incident lasted about five seconds in total. Once car returned to 75, I disabled cruise control for remainder of journey. This was a 45 mile journey and the issue did not surface until about 35 miles in to the journey. Because this has happened before, I was mentally prepared for it this time and wanted to see if the car would eventually stabilize back to the 75mph programmed speed. In two prior incidents in late 2021, the braking was severe and without warning so in those instances I immediately deactivated system by pressing brake pedal. The incident I report now also had no warning, good weather, no cars within about 100 yards, and no sun glare at all. Road surface was very good as it had been recently improved in 2021 so lane markers were excellent as well.