To my knowledge in Faerun, Drow male cannot become a Cleric of Lolth. Which is one of the key characteristics of a typical evil Drow society which is predominantly sexist and racist.
Surely it is a mistake of Larian and it will be fixed, right?
Or did the Lore change to be more "SWJ PC"?
Hey, go with it! That would explain why he's not part of the society anymore, but Lolth is a goddess of Chaos and she loves when shit like this pops up. Hell, she loved it when Drizzt broke from Drow society and caused all kinds of trouble for them. Come up with a really cool backstory to go with it. Lolth doesn't mind, trust me. :P