How would you pronounce the surname 'Chambliss'? With a long or short 'a'?

I pronounce the following surnames with a long 'a':

Chambers
Chamberlain

But I pronounce Chambliss with a short 'a' like the one in 'and.' I heard a couple of people pronounce Chambliss with a long 'a'--and it sounded odd to my ear. I'm just wondering whether I'm out-of-the-loop with how people generally pronounce this name.

I've never heard that name WW. Is it the name of a man or woman?

Man or woman: it's a family name.

Sorry, I didn't know the meaning of surname. Here we say "nom de famille" (family name)

Well, I apologize for using anecdotal evidence, but where else to go to answer the question: "How do people pronounce?" There is a lovely lady lawyer here in Western Washington whose last name (surname, nom de famille) is Chambless. She claims that it is Southern. And she pronounces it so that the first part rhymes with "ham."