Acidity of primary and secondary amines
Have you taken into account that there is a $\ce{-CH3}$ group attached to the top N which has +I effect i.e., electron donating effect?
$\ce{-CH3}$ group will destabilize the negative charge on N formed after the release of proton.
Electron releasing group decreases acidic strength of a compound. So in this question proton of primary amine is more acidic and that of secondary amine is less acidic.