Version 5.4.1 is here, bringing the return of social co-op and assorted bug fixes. There are also two confirmed bugs with social co-op. Check below:
1. Using LINE to play multiple social co-op sessions repeatedly can lead to co-op URL's not being created correctly.
Fix: Exit out of the LINE app completely and restart it.
2. Facebook co-op doesn't function correctly in some cases. We're currently investigating this bug.
3. New Striker Bonuses do not drop from social co-op or local co-op as they no longer exist in the game. They have been replaced by mission log orbs. This is a display issue and old carryover text from previous versions. This display issue will be fixed in the next version update.