I have a system message that the Instigate Defection assignment was completed but it didn't appear in the Completed list nor in the Assignment Log. I received no rewards at all. The doffs I sent on the mission are gone.
I also completed an In Game bug report, ticket 1,950,350.
The DOff mission Instigate Defection said it completed in the chat log while I was doing the mission Shutdown. After the mission ended, I went to the DOff interface and Instigate Defection was not listed as Completed or In Progress.
You'll see in the screenshot that the chat log shows Instigate Defection completed, followed 2 minutes later by High Speed Maneuvering. It also shows that I have no 'completed' assignments, but the Assignment log does not show Instigate Defection in the list, but it does show High Speed Maneuvering and a number of later assignments. Defection is simply gone.
Perhaps notable is my DOff roster was full (100/100) when the mission completed, but it should have just prevented me from collecting the reward until I opened a space...not make the mission vanish (with the doffs??)