1, the oven temperature is not enough, or inaccurate, the actual temperature may not be 160 degrees, or the oven is not closed tightly enough heat;
2, I saw you write "eggs, gluten-free flour, honey, sugar, mixed with the beating of the "I'm a little confused. You should beat the eggs or egg whites separately, then mix them with the flour (which must be low gluten) and other things after whipping. That's what makes it fluffy.
The best way to bake a fluffy cake is to beat the egg whites separately, and mix the egg yolks separately with oil, milk, and low gluten flour, and then mix them with the whipped egg whites in a certain way.