How is interest calculated and paid out in a savings account?

I had 130k in a Macquarie Bank savings account (made when the welcome rate was 4.5%). By my calculations, I shouldve received around at least $480 in interest for the month of May. However, I only received $274.

My calculations are as follows: ((130k * 4.5%)/365) * 30. Is this wrong? Why have I only received $274?