Yeah, my full names are Jeremia Josiah, and on my work permit they wrote the Thai version as เจอเรเมีย โยชิอา. I cannot figure out why they chose to use จ for the J in Jeremia but ย for the J in Josiah. Both are pronounced the same and I would consider จ the correct choice. I would consider ย more correct for representing a word with Y.

That's hilarious. The one I always notice is ก getting romanized as a K, ie Kanchanaburi or กานต์ becoming Karn.