NHTSA Complaint #11562189 — 2023 TESLA MODEL Y

I was driving in left lane of highway at night with cruise control engaged, traveling 70mph. Autopilot was NOT engaged - only the Traffic-Aware Cruise Control. I turned on my right turn signal to change lanes. At the same time a car came up behind me in the left lane and was tailgating me. As I began my lane change, my Tesla did a hard brake that slowed it down considerably and was not initiated by me. I had to accelerate hard to recover, and don’t know how the car behind me didn’t rear end me. There were no cars close ahead of me in any of the lanes. There was no warning displayed or sounded by my car. This vehicle had done the same thing more than once in the days prior to this incident, but in less dangerous situations and in the daytime. The car has not been seen by any service center, but I will be reporting the malfunction to Tesla. The car is new and had been on the road 12 days when this incident occurred.