As we know Fiverr is evaluating each profile on 15th of the Month.
Whenever Buyer is not responding and we ask them again and again for details for the gig to complete the order but still no luck.
So the order will be cancel after 3 days as we will ask for cancellation and mentioned reason there that the buyer is not responding.
So In that case, there is no fault on seller side.
Still our completion ratio decrease once the order is cancelled.
This feature is not safe for Sellers. This technique can be used to decrease reputation of our other competitors here on Fiverr.
So Please Fiverr Technical Team and Support Team, please fix this issue.