F-35B model is special in that its computer software can automatically trigger the ejection seat without pilot input.

This is because when it is near the ground vertically rising or descending it could crash faster than a pilot could do a manual eject.

A and C model F-35 computer software is not allowed to do this.

https://www.thedrive.com/the-war-zone/the-f-35b-can-eject-its-pilot-automatically