After completing 20 assignments and several sickbay assignments on my transferred character, the above happened. The debriefing section scrolls about three screens long before you get down to the actual assignments and is completely empty. It says a sickbay assignment is complete, but it can't be closed. It's also taking up an assignment slot, despite being sickbay and not an assignment.
The duty officer was available for assignment. Sending them out lead to the same screen above, but with the right panel blank. The long empty debriefing panel is still there and one assignment point is still unaccounted for.
Once this bug occurs, all newly completed assignments go into the same purgatory - they cannot be completed, their duty officers become available again, and the assignment point is not freed up.