I would be much obliged if you could say why. I really love to learn these vernacular differences.
https://dle.rae.es/mordita?m=form
https://es.wiktionary.org/wiki/mordida
https://es.wiktionary.org/wiki/mordita
Because I learned this from informal situations in the US something like 30 years ago, it stuck. But, surprise, surprise, the pronunciation was just an approximation, and led me astray.
Mordida it shall be forevermore.
Muchas Gracias.