In mid-January, we encountered a brief bug where Missions with no future start date failed to launch immediately as expected. This issue was caused by an internal date/time error and was resolved within a few hours. After the fix, all Missions launched correctly, and any Missions affected by the bug were launched later in the evening unless manually corrected by the teacher during creation.
Since the start of the school year, we had a bug where a question added to a custom activity and then deleted would remain "invisible" in the activity. The question couldn't be re-added, and trying to move other questions around the deleted one caused errors. All of these issues have been resolved, and deleted questions now delete correctly. They can also be re-added while editing a custom activity.