Learning to play this is tricky, as it requires a mix of special fingerings & manipulating your mouth and throat position to get overtones. It can be challenging to learn, or downright frustrating if the fingering chart you’re using works against you. I’d actually given up on it for years, but in 2013 I finally decided I’d try again, and, working off a chart made for Yamaha alto saxes (but which didn’t work on my tenor) I experimented, through trial-and-error, till I found a set of fingerings that mostly worked for me.