As the title suggests, Task #12 has been completed, but it will not unlock and allow for the next sub-task to be started.
#Task #12 Finished, but not unlocking
late carbon
upper kraken
Some tasks only unlock after reaching certain milestones
royal rock
The task itself is locked, unlocked tasks look like the first #11 task in your image.
maiden flume
It was reported a few times that players delivered "locked" tasks. We noted it down and will try to improve the visuals to communicate it better.
late carbon
ty for the clarification!