Typically when we see this it occurs with a hybrid architecture. I don't know if this is what you have, but if you do then can you check your technical workflows for the Mid-Sourcing workflows. There should be one for "Logs" and one for "Counters". If these workflows are not running then they won't pull the proper status of the delivery or the logs back from the Mid even though the delivery itself has been sent out.
In addition, since the tracking workflow is a separate workflow you'd still see opens and clicks, which is what we are seeing here.
Lastly if ever needed, you can make a manual call to update these statistics using the "Recompute delivery and tracking indicators" function (see steps below). One important note however is do not use the steps below on older deliveries that are outside of your configured data purge range (can be found in the deployment wizard's purge settings window). If the recompute attempts to pull from a purged entry all data on the delivery will be reset to zero.
1) Select the desired delivery, right-click and go to actions
2) Select Recompute delivery and tracking indicators