Hello,
I am sorry, but I have to report again, in 2020R2, I met status issue again.
Look below: The status of SO is obviously should be completed, because shipment had already been completed.

It looks like in 2020R2, due to unknown reason, we got now and then status issue.
It is not rare cases, it happens every week. And other users have also confirmed this kind of issue.
It might be the new “workflow” mechanism has some issues in it.
Before the developing team to find the root cause, I do believe a manually validation would help.
See my idea below:
That user manually trigger the system to recalculate. Like the issue I show above, the system would know the shipment has been completed and so the system can modify the so status to correct.