Dictionaries give the latter as an alternative pronunciation.
This is because the character 初 (sho, alternative pronunciation: hatsu) also means first, new or beginning in Japanese.
Self was unable to ascertain at what point the alternative pronunciation came into occasional use, but claimed that as of 1995 it had died out.
It is also possible that the European sources correctly recorded alternative pronunciations and dialects of the indigenous people.
While generally pronounced as "ess-pee-eye", an alternative pronunciation of "spy" can sometimes be heard.
An alternative pronunciation for Daventry used by locals is 'Daintree,' but this has become less common.
Shōgen is also an alternative pronunciation of the name of the Jōgen era (1207-1211).
About 100,000 words in British English with alternative pronunciations.
It was my sister who first pointed out its alternative pronunciation and it seems to have got stuck in my head.
Over 146,133 words in British English with alternative pronunciations.