Its origin can be traced way back from the Spanish period. Bohol was one of the major colony settlements during that time as evidenced by the many stone structures built all around the island that we still see today.
The Spanish language has certain letters that are pronounced differently from the English alphabet, for example letter J is pronounced as H in Spanish (i.e. Jaime), double "LL" pronounced as Y (i.e. llave - keys, llantas - tire rims). Interestingly Y is pronounced as J. Spanish word like playa meaning beach is pronounced as "plaja" . The most famous phrase that Boholanos are being quoted for is the phrase "Wa jamo", the word "jamo" is derived from the Spanish phrase "ya no" pronounced as "ja no" meaning "no longer" and it also means "nothing more". Even to this present day, Boholanos are still pronouncing "Y "as "J" including the Visayan vernacular words and phrases.
So every time you hear a Bol-anon pronounced "J" in their words and sentences, think of it as a Spanish cultural influence deeply embeded in the Boholano tongue.