not getting ahead of yourself, this is good to look at from all angles…
the saxophone can be a wild beast at times and you are finding this out!
when I was about 2 years into it I kept screwing up on middle G.
that note for me just wouldn’t come out right as the others did.
my teacher made me play that G for 20-30 minutes at a time.
straight on, from the F#, from the G#, loud, soft, tonguing it, no tongue etc
after a couple days of this I was able to hit it perfectly.
if it’s just one or 2 notes I would assume it’s not your equipment and so do what I did for a few days to see if you get over this hump.
let me know how it goes.