The launch director has called an anomaly, resulting in the end of the mission. We'll share more information as it comes to hand.
— Rocket Lab (@RocketLab) September 19, 2023
This is really bad for them since they also had a failure in 2020 and 2021. With no failures in 2022 the industry was hoping they had sorted things out but now it's obvious that their rocket will struggle to improve its ~94% success rate. 36/39 is fine but not great.