Sure thing!Sorry I am late to the party! I'm so sorry you lost your babies. I've opened boxes of chicks that didn't make it. It's heartbreaking...
I agree with the observation that Pekins seem to have more trouble. It seems like they have more needs than others because of their size. I've never brooded one, tbh. I have an adult Pekin now, but they are the breed about which most people post concerns, I think.
Your setup looks great! Im jealous! Better than mine. But I have never used heat lamps for any birds, duck or chicken. I've always opted for heating pads. I make a cave for chicks, and for ducks, I put a cave over the heating pad. I don't much care for the idea of 24/7 light and the risk of fire. Regardless, I know that ducklings don't require as much heat as chicks do. Try moving the lamp as the others suggest.
And I do have duckies, but @Miss Lydia and @shawluvsbirds have far more experience than I do, but thanks for the tag. Makes me feel important!