Good but flighty?

Using to tune my bass, and it works with all the notes except an open A for some reason. Like, all the other strings and fingerings work but it keeps telling me my A string is an E, and I know its not THAT out of tune. But it seems to work with my clarinet and when I hum so maybe its a low note thing. Would recommend to non-bass players.

EatingYourBassClarinet about Musician's Kit - Tuner, Metronome, and Sound Recorder