From my comments:

Chapter 6 -- Sir William Lucas's
Darcy agrees (dismissively?) that Lizzy expressed herself well with Colonel Forster. Drawn into speaking one sentence. Probably would have liked to say more, but Charlotte grabbed Lizzy for music.

From ch. 6:
On his approaching them soon afterwards, though without seeming to have any intention of speaking(italics mine), Miss Lucas defied her friend to mention such a subject to him; which immediately provoking Elizabeth to do it, she turned to him and said:

"Did you not think, Mr. Darcy, that I expressed myself uncommonly well just now, when I was teasing Colonel Forster to give us a ball at Meryton?"

"With great energy; but it is always a subject which makes a lady energetic."

Not another word from Darcy. You appear to infer a desire on his part to start a conversation; I don't.

From my comments on chapter 10:
"Darcy tries twice to get Lizzy to dance".

From ch. 10:
After playing some Italian songs, Miss Bingley varied the charm by a lively Scotch air; and soon afterwards Mr. Darcy, drawing near Elizabeth, said to her:

"Do not you feel a great inclination, Miss Bennet, to seize such an opportunity of dancing a reel?"

She smiled, but made no answer. He repeated the question, with some surprise at her silence.

Again, I do not see this as trying to start a conversation.