Zucchini Bread

This is Martha Stewart's zucchini spice bread. https://www.marthastewart.com/318960/zucchini-spice-bread She made it with fresh zucchini from her garden, I'm sure. I, however, had to buy zucchini from the farmer's market. (Buy zucchini? I never thought I'd write those words. I feel lost without a garden.) Even though I have made this in the past, and it looked like Martha's, this time it did not. Not at all. It flopped. It tastes good, but it collapsed. Could it be the humidity? It was a high dew point day. Or maybe my baking powder is bad? It had been moved from place to place. Maybe it's the quirky oven I'm still learning. Ah well, mistakes happen. It's part of being human.