Playing as a Rogue Seldarine Drow, the Illithid dialogue option is completely missing during the encounter with Flind. The bug seems to be specific to the Drow race, as other party members such as Lae'zel and Shadowheart do get an option to use the Illithid power.

[Linked Image from i.imgur.com]

Another dialogue bug specific to the Drow is in Blighted Village, the encounter with Fezzerk. If Wyll isn't present or the player tells Wyll to stand down, a cutscene should play where Fezzerk is quite restless and uneasy in the presence of a Drow. However the cutscene does not play properly and instead looks like this.

[Linked Image from i.imgur.com]