I played a long co-op game with a friend (2 player co-op). During this game we received the 3rd and final crypto key I required for the core. Upon finishing the run (we lost during the core boss fight) co-op friend (non-host) left the game and then I saved and returned to main menu. I rejoined the solo saloon and upon going to the hacking station the core still has one active core defense and no crypto key was registered. All other meta progression was kept from the run.