OnXXX, at approximately 5:00 PM CT, my 2025 Rivian R1S was involved in a low-speed rear-end collision at the intersection of [XXX] and the [XXX]. I was merging onto the service road (posted speed approx. 55 mph) behind another vehicle that began its merge through a stop sign, then stopped suddenly. I was moving forward at approximately 5-10 mph while checking oncoming traffic to my left. The vehicle's Automatic Emergency Braking system did not engage, and no forward collision warning was displayed, before I struck the vehicle ahead. I applied the brakes manually only after impact. No injuries occurred. I am reporting this because Rivian has previously disclosed to NHTSA (Recall 25V-585, XXX) a related defect in which its ADAS software misclassified a lead vehicle at low speed. My incident involved the same general failure pattern - the system not correctly responding to a slow-moving vehicle directly ahead at low speed. Additionally, the vehicle's onboard camera/recording system (Gear Guard) had been disabled by the manufacturer service center during a repair visit completed earlier that same day, and was not re-enabled before the vehicle was returned to me. As a result, no independent video record of the incident exists. I have submitted a formal written request to the manufacturer to preserve all EDR, ADAS, and vehicle telemetry data from the date of the incident, and that review is ongoing as of this filing. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT