There was delay.
Later Clinton wrote that on the basis of assurances from Admiral Graves he hoped to get away on the twelfth.

A British officer in New York describes the hopes with which the populace watched these preparations.
The fleet, however, did not sail until the 19th of October.

A speaker in Congress at the time said that the British Admiral should certainly hang for this delay.
On the 5th of October, for some reason unexplained, Cornwallis abandoned the outer parallel and withdrew behind the inner one.

This left him in Yorktown a space so narrow that nearly every part of it could be swept by enemy artillery.

By the 11th of October shells were dropping incessantly from a distance of only three hundred yards, and before this powerful fire the earthworks crumbled.