I think this is one of those words that appeared in print before anyone actually ever tried to pronounce it , so everyone can only guess, including the first person to make up the word. Ergo there is no "correct" way, only a consensus (or not) which arises either from which pronunciation is "easiest" or by analogy with a word they do know (did you learn about metadata or metabolism?). While we're at it, think about heliCOPter : roots are helico (spiral) and pter (wing), but it's difficult to imagine anything other than heliCOPter
Interestingly, it's usually the other way round - everyone knows how to say a word and the argument, ahem, discussion, is over how to spell it.