One note flat, changing breath doesn't help
Bought a Generation B flat whistle, and the actual B flat note is too flat compared to the other notes (whistle is warmed up and double checked it on a tuner). If I try to change my breath to bring the note up, it doesn't sharpen up before popping into the next octave.
I popped off the mouthpiece to see if I could tune it a bit. I figured if I could get the B flat up, I could back off a bit breath-wise on the rest of the notes. But there's no wiggle room to push the mouthpiece further on.
I've read about issues with these whistles in general, but I've also read the complete opposite, where people say the whistles are fine. Yes, it was cheap, but I'd hope that "cheap" ≠ "not in tune with itself".
Are they, in fact, prone to issues, and I've been hit with a baddie? Is there anything I can do to get it in tune, or should I just try a more "reliable" whistle?