but the users must manually press F5 to see the new line. And that is the problem: The refresh of the open document shoud happen automatically. Because the user shoud not forget this new line. Is there any way to do this?
It looks like (correct me if I'm wrong) you opened a Support case for this today as well, and it seems like they possibly identified why you are seeing this (a defect SPR 5341296). Can you update this thread, if that is the case?