I'm in high school, and it's my first year playing the sax. That might be why. I got a new mouthpiece (Rico alto 3c) and ligature (Rovner dark 1rl). I'm having more issues than I used to, and I can make low notes with a rolled lower lip. The problem is, when I use the lower lip embouchure, my cheeks start feeling like death after a few bars. The reason I chose the Rico mpc instead of a Yamaha 4c, which is a good beginner piece, is that I play Rico reeds. The reeds and mouthpiece are the same brand, so I thought they'd match up well. I guess not. If it helps, I use a Selmer AS400 Alto.
Nick. I think that this is normal stuff for a beginner. I’ve been playing for nearly 3 years at 60 to 90 minutes per day, and my embouchure is still developing. A few notes for the future.
1) Assuming Saxoclese specifications are correct, the 0.070 tip opening on on the Rico is going to most likely help you play louder. That will probably be helpful in the future, so it was probably a good purchase if you plan to stay with band.
2). Changing mouthpieces to a larger tip opening is always hard on your mouth. Not much you can do but play it every day. In a couple of weeks you will get used to it. (You will feel better if you go back to the 4C, but you won’t get used to the new mouthpiece unless you play the RICO).
3). Changing ligatures can also a big deal, not just the mouthpiece. I ended up switching to a Rovner when I was fairly new. I recall it taking a lot more lip control to have it function well. (I needed to develop better air support too!). This could be causing embouchure pain, not just the new mouthpiece. In the end the Rovner mellowed out the sound of the mouthpieces. (Helps control brightness.....which can be an issue on beginner mouthpieces). I seem to remember it taking men 4 to 6 weeks to get used to my Rovner when I first got.....and I did not change mouthpieces simultaneously.
You might want to take the interim step of playing the Rico 3C mouthpiece with your old ligature....and then after you get used to that, add the Rovner.....take the adjustments one at a time, rather than all at once.
Good Luck!