Why did the Firefly Alpha rocket fail to reach orbit on its sixth flight?

During the April 29th launch of the Firefly Alpha rocket, a critical component failure occurred during stage separation. This video examines the loss of the second stage nozzle extension and how this mechanical issue prevented the mission from reaching its intended orbit.

On April 29th, the Firefly Alpha rocket attempted a mission carrying a payload for Lockheed Martin. During the separation of the stages, the nozzle extension on the second stage was lost. This component is essential for engine performance, and its absence meant the rocket could not achieve orbit.

The mechanism for stage separation remains a subject of analysis. While some rockets use piston pushers, observations from the second flight suggest that Firefly may utilize a gas-based system, effectively blowing gas into the interstage to force the stages apart, similar to a cork exiting a bottle.

Source: What Went Wrong On Firefly's 6th Rocket Flight? Did The Nozzle Fall Off The Second Stage?