I have a pawn installed with combat chip and wear a cartridge. After possibly getting a head shot (not sure) and get revived by cartridge the combat chip somehow stuck in the assassin mode and the ability to activate combat chip is no where to be found.

My guess is when the shot destroy the brain causing the death also destroy the combat chip and when revived it didn't properly come back.

it's just my guess, since I didn't notice this way after the crazy raid I'm not sure how exactly things happened.