How to prevent bottoms from burning when open baking with sweet inclusions?

Recently got a Rsckmaster RM2020 two weeks ago and have been baking regular and different cheesy loaves with great results. Today I did a test batch of espresso chocolate chip and cinnamon chip loaves and the bottoms got somewhat burnt, I suspect it’s the sugar. I have zero open baking experience and have always made these in Dutch ovens or pans. Do I need to stick to using pans or is there something else I can try? My open baking is at a lower temperature that I used to bake in my home oven. I used to bake at 450° F the whole time but with this oven I preheat to 430° F and then drop to 375° F once I add the loaves and steam it. Those temperatures worked great for regular loaves.