It sounds like you may have an issue with the sensitivity of your stud finder, as it is detecting metal in the same spot as the studs. The metal option is likely detecting something else in the wall, like pipes. Try increasing the sensitivity of your stud finder to see if it will pick up the studs more clearly. If that doesn't work, then you might want to invest in a different stud finder. There are many reviews in this subreddit about various stud finders that can help you make the best decision. Good luck!