Hugito: Welcome to SOTW. You may not have the mouthpiece sited properly on the cork. I'd try to tune several notes before checking overall tuning.
I know many folks like to tune to certain notes . . . heck, there's probably several texts that advise tuning to a certain note. But I've always tuned to concert Bb in two octaves (G on your alto). Once I have those two notes dialed in, the whole horn tunes well.
Next, if possible, have another player try to tune the horn using that player's mouthpiece/reed. I doubt if the horn is at fault. DAVE