All figures looks ok to me. The May value looks correct assuming your term is about 29 years. Your interest calc of €499 is roughly what it would be if they added the interest in monthly but that's not how AIB do it.
Basically you pay monthly and every quarter AIB adds on the interest. Obviously 48 days is not a quarter but there's always a bit of settling down after drawdown. I'm guessing that June 16th and then every 3 months thereafter will be the date your interest is capitalised. It all works out more or less the same whichever approach you take.