While looking up some Old Testament names I found Jogli as the name of a man mentioned briefly in the Book of Numbers in the Old Testament.
Who's Who in the Old Testament by
Joan Comay says that the Old Testament name Jogli meant "my redemption" in Hebrew. Given how many of the other names on this list seem
German, a
German pet form of
Jakob is still possible for your ancestor, but this gives another possible derivation.