To build on this- you can find adapters for most sizes/joints on wish, DH Gate, sometimes Amazon, and at most local smoke shops if you’re not looking to replace the downstem. I’ll link one here just to give an example. Hope you can find something soon! :)
Edit: after rereading the post, I just realized that I might’ve linked an adapter that is the literal opposite of what you might need. Soooo this one is what I’m assuming you may need!