Here's why:
* "Jonny Quest" was a television show, not a comic book series. It was broadcast on ABC from 1964 to 1967.
* The episodes had titles, not issue numbers. "Monster in the Monastery" is one of the show's episodes, but there wasn't a 25-part story with that title.
* No official comic book adaptation with those specifics exists. While there have been several Jonny Quest comics over the years, none match the description you provided.
Perhaps you're thinking of a fan-made project or a misremembered source. If you can provide more context, I might be able to help you further!