The bug listed t here is the level 6 crew missions returning less materials than intended, not the lack of mission types withing categories.
The lack of mission types/within categories has been around since day 1. The workaround used in the past has been to cause an instance load. ie: leave ship, look at available, enter ship, look at list. That type of change can cause a reload of missions and get a change. It doesn't always work, but if you have enough time you can usually get what you want even if it isnt the severity (moderate/rich etc) you want.