This means that you have delivered before the time of your order. When the delivery time of the order is finished, it will continue to decrease if you deliver after that, which will have an effect on your gig. The notification comes from Fiverr 12 hours before your last, try to deliver before this notification arrives.
I can't get orders for many days. I have 9 out of 5 star reviews, all positive reviews. But even after that I am not getting any order. Those who are experts, please check my profile.