I used to have the same problem with Faendal, but not anymore, he currently uses an unmodified/unenchanted glass bow. The problem stopped for me when I gave him a hunting bow, go figure... Maybe now the game sees that he has a hunting bow in his inventory so the game does not feel the need to spawn a new hidden hunting bow in his hidden inventory, and Faendal noticed the better glass bow in his inventory so he prefers that. But it could be that I'm just lucky though, I guess I will find out soon enough as it's about time to give him an ebony bow (fully upgraded this time).
