I have half a dozen like this as well.
It seems that they are not being sent at the moment as the tasks were '3 second errors" in the challenge and have been removed from the proirity clean up list, if you look you can expect to see a few validation failures in the task list. They should go out in a few days when the more urgent stuff is gone.
At least you know that if it is a prime you will not be the double checker!!
EDIT : I have done some checking on mine and they fall into 2 classes.
a) Those I did not complete in time for the challenge, which are now going to wait for the clean up tasks.
b) Some sent out 10 to 12 hours after the end of the challenge before the '3 second errors' were removed from the clean up list.
I expect they will be sent within the next week or so as the clean up tasks run out so the wait should not be too long and there is no problem.
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