Puzzle Inaccuracy – Logic Grid Puzzles Review

The presentation is nice, but the Grandkids’ Birthdays puzzle made me lose all hope for this. There is a strict logical conclusion that is very easy to follow (no leaps of logic are made, and everything is supported by the clues), yet it says my answer is wrong. I have done the problem no less than five times looking for a possible mistake, and I always get the same answer. I have scoured the puzzle clues to see if there may be some small wording I missed, but there is nothing I can see. I firmly believe there are either two valid solutions to this puzzle or the puzzle is bugged. Feel free to prove me wrong, but I can’t enjoy this game knowing I have to question the legitimacy of each puzzle.
Review by Murffurff on Logic Grid Puzzles.